Using Premium Unleaded Petrol

Unleaded Petrol Pump

Which petrol is best for your vehicle?

Have you ever used Premium Unleaded petrol in your vehicle instead of Regular Unleaded? Did it seem to go further, dollar for dollar? Did it have any noticeable effect at all?

If your car is optimised to run on Regular Unleaded 91 RON (Research Octane Number), then using PULP may have a marginal effect on the fuel consumption and cost saving.

So if, hypothetically, a vehicle was designed to operate on any octane (which is never the case), using 98 RON would give a seven per cent increase in power or a seven per cent decrease in fuel consumption compared with using 91 RON. Cars that are designed to run on PULP 98 RON may still run on 95 RON but you may lose around three per cent of power, or increase fuel consumption by this amount.

Therefore, if ultra premium fuel costs more than seven per cent more than 91 RON, is it economically unwise to use it?

The simplest advice is to use the octane recommended in your owner’s manual.

Have you used Premium Unleaded and noticed any improvements in your vehicle’s fuel economy or performance?

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This entry was posted in Fuels, My Car and tagged , , , , , by Jack @ NRMA. Bookmark the permalink.

About Jack @ NRMA

Jack is the NRMA’s advocate and champion for vehicle technical and environmental issues. He has been with NRMA for 24 years and previous to that worked for a vehicle manufacturer and ran an emissions laboratory. He analyses new technologies, suggests any testing required and manages the NRMA’s involvement in national programs such as ANCAP, the high speed crash test program that provides safety ratings for purchasers of new vehicles; the Used Car Safety Ratings, that provide similar ratings for used cars; the Child Restraint Evaluation Program, to rate child restraints; and the Consumer Rating and Assessment of Safety Helmets (CRASH) to rate motorcycle helmets. Jack also presents NRMA policy and test results from these programs in the media, so you may see him on TV or hear him on the radio.

114 thoughts on “Using Premium Unleaded Petrol

  1. Ah, confirmation. I have obtained around 8-10% improvement in fuel consumption in my Toyota Avalon. I use the 98 octane only on longer journeys as I think the margin is a lot less in city driving. I always take the price differential into account, although I understand the 98 fuel burns better.

      • No… The octane rating isn’t about the energy content of the petrol, its about its resistance to self igniting at a given temperature. When the air/fuel mixture is compressed by the engine it heats up a lot. Higher compression ratio engines heat the mixture more, so they need a higher octane fuel to prevent pre-ignition. Putting a higher octane fuel in a car which has 91 octane recommended by its manufacturer may give a slight improvement to fuel economy, but it likely as not will cost you more in money than you save in actual litres. Even a small car may cost you an extra $3.50 a tank to put 95 in it.

        • Is the performance increase with PULP the same for marine engines? I have a new 5.7ltr engine (currently 20hrs total) on my stern drive 6.2 mt Bowrider and I’m interested in opinions if I should change to premium fuel.

  2. I have found that by using PULP in my Getz, I get better mileage and power. I alternate between PULP and ULP.

  3. Regardless of any fuel consumption benefit, I understand PULP is “better quality” fuel with respect to lower sulphur content than ULP which apart from pollution/rotten-egg gas, is also the cause of engines with Nikasil bore coatings being damaged as suffered by Jaguar and BMW (and other European brands). Also less chance of PULP being spiked with ethanol and other harmful/inferior energy content contaminants. Although designed for 96-RON, my Daimler Super V8 can run OK on 91-RON, but where available, for above reasons I always use 98-RON.

  4. I have a VT series 11 year 2000 model commodore and always use pulp on longer trips if the price difference with standard unleaded is below 9c/litre. The improved performance and mpg works out cheaper paying up to the 9c extra. I find the performance gradually drops over the next 4-5 tank fulls of standard so I am assuming the higher octane petrol helps clean out the fuel system.

  5. I use only PULP (required for Forester XT) but have found in the past that Castrol has better fuel economy then Shell but little difference now. Also have much better fuel economy in winter then summer (better then 10%) probably mainly due to AC.

  6. My senior mechanic cousin strongly recommends using PULP on long trips or in every other tank to keep the injectors and heads clean, and it certainly does give a small but noticeable improvement in power, economy and responsiveness.

  7. I never use anything but 98 RON in my 2000 Commodore VT SS. The improvement in performance and economy was well worth the extra 9% price. I started getting a 10% improvement in fuel economy. On a trip with a load and using the performance for overtaking, it is easy to get 10 litres/100km. Best has been 9.2 l/100km. Not bad for a 5.7 litre V8.

  8. I drive a 2000 Camry Touring (manual) and have found using PULP decreases fuel consumption and greatly increases responsiveness. On ULP the engine hesitates for a fraction of a second when I accellerate hard in any gear. I am no boy racer or hoon but have been a “petrol head” for all my motoring life of 45 years and like to think I’m doing the right thing for my cars.

  9. Previously I owned a Mitsubishi Gallant VR4. It definitely benefited by using PULP. It ran smoother, quieter. I feel I achieved a small increase in fuel economy, but it was never enough to off-set the difference in cost at the pump.

    I now own a 2002 Nissan X Trail Ti. My experience is based on purely metro driving. I have tried both PULP & 95-RON. I use STD ULP for this car. The Nissan Dealer, where I get it regularly serviced also stated to me that there is nor benefit in putting PULP, as the engine is not designed to take any advantage of it. In both cases, I cannot feel or see any improvement in pick up or economy. The few percent difference mentioned above can easily be achieved by simply driving a little smoother and lighter.

    PS: I am actually going to convert the X Trail to LP Gas in 2008. I estimate that I will break even in approximately 14 – 16 months of driving. The 50L tank will go in the Spare Wheel Well.

  10. I used to drive a manual Subaru Impreza 2.0 (Year 2000). In the days (2003/04) when petrol was about 80-90 cents and the difference in 91/95 octane was about 5c, there was definitely benefit in using 95 octane (BP) fuel, compared to 91 octane. The car using 95 Octane was far more responsive under 3000rpm, and economy was also consistently better by about 5% (I kept tabs over many tank refills of different grades). I cannot recall what minimum grade the Impreza required – it could have been 91.

    There was no appreciable performance difference between 95 and 98 Octane in this car.

    In short, the extra 5c cost of the 95 Octane was worth it, 98 Octane not.

  11. On 2 month holiday with Prado 4 litre towing a caravan no difference in economy or power noticed.I was determined to try the high octane to see for myself as I had many wild claims and advice directed to me.

  12. I have a 2003 Nissan Skyline 350GT for which 95 RON is the recommended minimum. Using 98 RON I have noted a significant improvement in economy in mainly country driving; possibly as much as 10%. Engine responsiveness also seems slightly better although this would be hard to validate without proper instrument based testing.

  13. I own a 2002 Nissan Maxima V6. I have tried ethanol fuel, ulp, and pulp. The car is unhappy running on ethanol, copes well with ulp, and I notice a performance gain with pulp. I have not noticed any perceptable difference in fuel economy with any fuel. Average fuel figures are 10.4L/100K. Like previous contributors, I use pulp on long journeys, and when towing. I generally use ulp for the cost saving, filling with pulp each fifth fill-up if no long journeys are undertaken within this period.

  14. I have only ever run 98octane in my Polo GTI as premium is recommended. It also has a different ECU tune (and must run a minimum of 98), and I have also run Shell Racing 100 octane, as it is able to take advantage of the higher octane rating.

    This seems to give better pickup from low rpm and come on boost harder, though seat of the pants is never a reliable measure. But I am prepared to pay the premium for any extra performance. Consumption seems similar, and very reasonable.

  15. I drive a 94 Mazda 626 2.5 V6. Great smooth engine but lacked low end torque. Like all engines tho it had its peaks at different rev ranges so i decided to buy a powerchip to take full advantage of using PULP. Without the chip i would be skeptical of its advantages vs price but in my case where i installed a chip to maximise the use of PULP i would recommend it. Smoothed out delivery of (now extra) power and torque throughout revs and slightly better fuel economy. At the end of the day, its the revs that determine economy. Lower revs equals lower fuel use!

  16. I am in no way mechanically minded! A few years ago, a stranger recommended we start using Premium Unleaded instead of Regular, especially on long journeys. We found that if the price differential between 91 and 95 was only 6 cents that we made a profit in mileage in addition to having so much better take off at lights around the city and suburbs. We have stayed with 95, or if necessary 98, even if the cost difference is more that 6 cents (or 10 cents for 98). You get so much further on a long journey, and there is so much extra get up and go!

  17. What a load of crap!!!!!!!!!.. I have two late model cars, I have tried E10, unleaded and premium unleaded and have found absolutely NO difference in either power or economy. These different fuels have been tried both city and country driving. Just another oil company con!!

  18. I drive a Jeep cherokee sport & find that when it’s carrying a load using regular ULP – say all 4 of our family – it will ping under the right sort of conditions. Usually under power, like going up a hill. It pings badly pulling the camper trailer. So I always use the highest PULP I can get when I need to do that. I undertand that our Australian fuel standards for Octane is one of the lowest in the world. What we call “premium” is standard in Nth America or Eruope or Japan – which is why so many cars from overseas need to run on PULP. (remember that the next time oil companies compare their prices to other countries)

    However I’m not so convinced about teh cost benefits commuting to and from work. My beef is, the oil companies charge far too high a premium for PULP. It is not justified. I’ve seen differentials well over 15%. That’s simply price gouging, for what is plain fuel in their other markets.

  19. I only use PULP in my 2004 Hyundai Tiburon, the fuel consumption is greatly improved. I have tried regular but I use about 4L/100km less using PULP.
    I don’t use all the power available but the car certainly runs very well using the better fuel

  20. Had a 99 SB Barina, distance from tank went from 380-400 ks to 520 switching to optimax when it first came out, with similar performance boost. Have 100 series (V8) L/Cruiser that gets 10/12% better milage on PULP than std ulp, with better low end reponse. Have Mazda 6 that requires 95RON but now have to use 98( 95 discontinued/ shell card supplied) with no measured difference except price.

  21. The theory & math is correct but the problem is ensuring you do get PULP. I drive a Pathfinder and have done a test over the same route(including return) with each fuel & result not really measurable. What is more disturbing is that the fuel bought in country gave me better fuel consumption than that bought in Sydney and there was a 1L/km difference with PULP and something like 2L/km between City & Country.
    The real issue of PULP & ULP is that we cannot guarantee that we are buying 91 or 98 RON without the addatives that reduce energy available. I think it interesting that the Quality Assurance Approval ISO 9000 is nowhere to be seen at the retail level of fuel companies and the NRMA is not pursueing it and is an indication of our mutual body failing us. Pathetic!

  22. Call me stupid, but I did about 4 tanks on PULP in my 1982 Mitsubish L300 van hahaha. I thought it gave me a little extra power but maybe it was a placebo effect… I wanted to think it gave me more power. I filled up this morning using regular unleaded. If i notice a decrease in power, I will go back to PULP.

  23. using PULP in my 98 V6 camry makes a measurable difference in both power and fuel economy but makes absolutely no difference at all in my wifes 2002 corolla, maybe due to the higher compression in the V6 engine. it is interesting to note that Toyota claims 4 kilowatts more from the V6 aurion when using PULP.

  24. I own a 1999 BMW 528i so I regularly use PULP and I haven’t gone into the difference it makes to unleaded 91. However, I have to say within PULP itself there has been quite a lot of variation in Km per tank of fuel when driving in the mtro area. There was one brand for which I would hardly reach 400 Km and when I changed to another brand I found it rose initially to around 450 Km – but then even sticking to this brand I found it varied from 410 Km to 500 Km. I feel we could do a lot for reducing greenhouse gases if we could just maintain the standard of our fuel, especially if I could regularly get 500 Km out of my tank and not 400 – that would amount to a 25% reduction.

  25. I think that the comments of David Saffell and Wayne need a response.

    David thinks that the claims are “a load of crap” based on his experience with his two late model cars. Fair enough, but that doesn’t mean the experiences of the other members writing here are wrong. As both the NRMA and the oil companies point out, it varies from car to car, particularly depending on whether the vehicle is tuned for the higher octane fuels. As we see here it works for some not others. Best to try it for yourself. For my car it works well for our son’s older Corolla it doesn’t.

    Wayne claims that what we call “premium” is standard in Nth America or Europe. This may be true for Europe but is not for Nth America. It is hard to compare Aus with USA because while Europe and Aus octane ratings are based on the Research Octane Number, or R.O.N., the US gasoline grades are based on both the R.O.N. and another measure, the Motor Octane Number or M.O.N. So octane ratings at the US pumps are not directly comparable with Aus octane ratings. The M.O.N. is almost always lower than R.O.N., so the combined or averaged octane rating is also lower than R.O.N. by a small amount, depending the exact hydrocarbon mix.

    So for example the US “regular” gasoline has a octane range from 85 to 88, “mid grade” from 88 to 90 and “premium” above 90. (Source: US Dept. of Environment). Generally speaking these equate to our 91, 95 and 98 R.O.N. fuels.

  26. what type of fuel is best for a bmw 320i (e46)? My dealer said to use unleaded petrol regularly instead of premium unleaded because unleaded is said to be better. is this true?

  27. Hi,
    I recently bought a 2004 Subaru Forester XT. I had heard a lot about fuel related performance in relation to the XT and did some experimentation whilst discussing fuel types with friends who own performance cars.
    Bascially, never use RON 95 on performace cars if you can afford a few dollars more for the 98. The difference is out of this world… and it’s much better for your car. In the RON 98 range of fuels (available in Aus) the common consensus between these car owners is that the new Shell fuel that replaced Optimax comes in a distant last. Mobil 98 comes in behind this and Caltex and BP versions give far and away the best performance. My personal preference is the BP.
    Good luck

  28. I have a 96 Nissan Sentra which I owned from new and it’s always been run on regular unleaded. Today I made the mistake of putting in 95…I haven’t noticed anything different yet, but I’ve mainly done city driving around Wellington, plus climbing short hills. I’m not mechanically-minded, so what should I be looking for? Also, I’m taking the family on a long journey during the holidays, and was wondering if using 95 for that would be advisable. Comments and suggestions from anyone would be appreciated..cheers

  29. will using 98 RON in a non-performance car (1997 nissan maxima, the handbook recommends premium unleaded) be at all damaging to the engine?

  30. The octane level itself in the fuel does NOT increase power. Higher octane levels in fuels only reduce the pressure at which the fuel detonates thus allowing more timing advance in an engine (or less retardation). This CAN give a power increase but unless the car is already retarding the engine from knock or the car is tuned with more advance, you will not see an increase in power.

    What you are NOT told is that generally these higher octane fuels also have a different chemical composition which DOES produce more power per unit when compared to standard ULP.

    These people telling you that Octane = Power are wrong.

  31. Following on from Andrew’s comments, a higher octane rating allows cars with engine management systems and knock sensors to advance the ignition timing further than with say 91. This gives improved fuel economy, especially on a long trip where light loads/small throttle openings allows very advanced ignition timing, hence better economy. A well set up engine management system will advance timing till detonation is detected and then back off a bit. Bourne out by the comments of those above who get good economy on trips.

    I have just started using 95 in my Commodore VX II. Car idles much better, smoother and more consistant and has better pick up. Have not noticed any lower fuel use as yet.

  32. well. i’ev a 1991 audi e80. not a performance car.
    with 91 octane she’s great on the flat, but nz is quite hilly, and i get a better than 10% economy when going ’round the mountains. could be becuase i hardly need any gas to go up them? i dunno. i’ve read about it, and it shouldn’t work, but who knows. i use bp as that’s all that’s available

  33. I have nissan 300zx and it takes the premium unlead,i used the cheap stuff u no the 10% ethanol and it has recked the performance of my car now my car dont run like it use to it surges now when i take off or just when i take it easy i will have to get it fixed now and it’s going to cost me a good amount of cash to fix the problem i will never use it again iwas told by a machanic that u must tune your car for it to run good on the ethanol petrol wish i new this b4 i used it.

  34. I drive a 2005 BF Falcon. The last month I have been using 95 RON as opposed to 91 previously and have noticed the avereage fuel cuncumption has dropped by about 2l/100km according to the trip computer. Im going to continue using the higher grade fuel.

  35. I have a brand new Toyota Kluger V6 (2wd) and have just completed 30,000km, mainly on looooong country trips around QLD, NT and NSW.

    The Kluger has a sophisticated computer display which shows in real time what economy I am getting; at that very instant, for that tank since refill and for the trip since the meter was reset.

    As well, it shows the last 6 trips’ economy, so I can get very accurate comparisons because I have been driving over very similar terrain and in similar driving conditions.

    I have tried all fuels available ranging from OPEL (the non sniffable stuff in central OZ), Ethanol blends (the label on my fuel filler says that 10% Ethanol is acceptable), ULP and PULP in its various forms from different outlets.

    Here is what I have found:
    On average;
    PULP returns 8.4
    ULP returns 9.0
    E10 returns 9.6

    This is mainly country driving, I find combined city/country cycles throws the whole thing out because one can never get the same conditions two days running but I generally see a full 1 litre change (8.4 goes to 9.4 etc)

    In the country I try to keep the rev counter hovering around 2,000 which equates to 110kmh and I use cruise control at all times except in hilly or badly surfaced roads.

    1. ULP fuels in many far south western QLD in general give very poor results. I have discussed this with other travellers who all agree. It doesn’t seem to matter what brand…. they all seem to be supplied from the one (un branded) supplier. (I often wonder if they are being supplied with E10 instead of ULP, or is it because most cars out there are diesel, so the ULP is stale)

    2. However, the independent (red white and blue coloured) outlets found around the big mining towns in western QLD have a “better” fuel than the usual big boys. Once I get beyond Dalby I always seek these guys out.

    3. Similar fuels in far western NSW are generally pretty equal, I spoke to a tanker driver who was filling a Cobar station and he said the fuel comes straight from Newcastle every other day so it is very fresh.

    4. I can detect an immediate difference when I change types of fuel. This “feel” is immediately confirmed by the computer and even my wife sitting in the passenger seat who can see the computer display will say “you have just changed fuels haven’t you…the display is showing it”

    Going to E10 is even more noticeable, but I couldn’t detect nor could the computer show any change with OPEL and non OPEL ULP.

    On a side note, immediately after each service at 10k intervals, the whole pick-up, gear change and general feel, changes (feels perky) for a about 100km until it returns to normal.
    The Toyota service manager pointed out that because the engine computer “learns” the driving style and adjusts things like gear changing points etc, that when a young mechanic takes my car for the road test he drives it like any young bloke…not in any way like an old fart like me will drive my pride and joy, so the computer re-adjusts to the heavier foot of the mechanic and then takes a while to re-adjust to my driving style.

    So I am happy to stick to PULP, (but not happy at the price). PULP gives me a nicer “feel” (smoother) and measurable improvement in economy. My last trip of 9,000 km to Uluru where I fastidiously recorded all my figures has proven this to me and I think that the extra economy overcomes the extra price, but I can’t prove that because prices change so much.

  36. I drive a 1989 Volvo 740 16 Valve, the recommended fuel is 95 octane for this engine. Running it on 91 octane, its performance and fuel economy is noticeably reduced. On the 91 Octane the engine is sluggish in performance. When I put in 98 octane, it goes like a dream with a very noticeably improvement in power! I always use 98 octane as it is the cleanest and best fuel for the engine available and it gives a noticeable difference both in fuel economy and performance to the Volvo 740 16 Valve. In a Wheels magazine review for the 740 16 Valve when it was new back in 1989, it was strongly recommended to use 95 or above octane. Which I am happy to do, as the extra cost of 10¢ per litre is offset by the fact I get more kilometres per tank and get much better and smoother performance. It is also good to know I am doing less harm to the environment as the 98 octane produces much less harmful emissions.

  37. Reading all the emails is very interesting. I have recently bought a new lawnmower. I was told to use Premium in it. I have been running unleaded Woolworths fuel, it’s been fine. Then changed to BP unleaded, it started to blow a lot of smoke for the first two minutes. So went back to the shop where I purchased the lawnmower and he told me all air cooled motors should have Premium fuel in them. Can anyone confirm this please? Also have a Mitsubishi 1995 Magna wagon which I just bought. Has anyone had experience with putting Premium in this car? Thank you, Dave.

  38. I drive a Volvo 850 SE and the Volvo definitely benefits from using 98 octane premium unleaded. There is a noticeable difference in throttle responsiveness, engine performance, smoothness and quietness of the engine when using premium unleaded. The price difference and extra cost is well worth it, I think it pays for itself in the long run with better fuel economy and a cleaner engine.

    I think though maybe, one needs to also go by the recommended octane for their engine which, one can find in the owners manual. For the Volvo 850 SE the recommended octane is 95 octane, with a minimum octane of 91. Which would to me imply that this Volvo’s engine is designed to run its best on 95+ octane, but will run on 91 octane with reduced performance. The knock sensor also adjusts the engine performance in response to the level of octane the fuel has that you are using. That being 91, 95 or 98 octane.

    I use 98 octane, but 95 octane is also fine for this engine.

    The noticable difference between using unleaded petrol (ULP) and premium unleaded petrol (PULP), has proven this to me on various occasions when I have switched betwen using ULP and PULP. The difference between the performance of the engine is like night and day, when using ULP vs. PULP. I would strongly recomenned anyone who owns a Volvo to use 95 or 98 octane.

  39. I drive a 2002 Renault Laguna, and have never used ULP, because PULP is what has been recommended by Renault themselves. Anyhow, out of curiosity, I once filled up my tank with ULP and and compared it with PULP. The result, I got less km’s with using ULP. Ever since that, I never used ULP again. I’ll rather pay more, and get more km’s and better benefits my car in the long-run. After all, it is only a 6-10 cents difference (well, that’s the difference in my location.)

    In conclusion, it all depends on the driver whether they choose ULP or PULP 95 or 98. For me, PULP 95 is what I use for 3 weeks, and every 4th or last week of the month, I fill up with 98 octane, just to give my engine a bit of a treat! As a result, whenever I book for a major service, I get told it only needs a minor service – so as mentioned in some of the comments above, PULP does really pay off!

    But no pressure on ULP users… Cheers!!!

  40. Got a question ? Would anybody be silly enough to fill a 40 plus litre tank size on 2 different occasions using different RONs?

    e.g. Put half a tank of UPL (ie.20ltrs 90 RON) & the reminder of the tank filled with PULP (also 20ltrs 98RON) on a single petrol station pump?

    Do you we can get an average of 94RON and save costs than using 40ltrs 95RON ?

    I’m asking in case somebody does that (let us know) and will there be any benefit to the car that even costs to fill overall? In case someone would put a 10 ltrs 98RON & a 30 ltrs 90RON, I wondered what will the average RON will be and probably will it save any costs then trying to use 40ltrs 95RON at one go?

    Please share your experiences or comments with us here.

  41. Interesting that the a lot of the views in the negative above drive heavy vehicles (4wds) and towing for example.

    A heavy ladened vehicle towing a van is going to be struggling to give you any extra power / economy – in fact why the heck for this application aren’t you running a diesel vehicle???

    As discussed PULP will vary from vehicle to vehicle. As a rule of thumb those more high performance vehicles where its recommend will see the biggest advantage. My Saab turbo runs 0-100 in 6.9 sec and gives me around another 150kms per tank highway cycle on PULP or around 80kms extra city cycle when compared to chucking the standard ULP. The noticable difference is incredible – only need one tank of standard ULP and the drop in power and economy is drastic. Its designed to run on PULP.

    The other thing missing from this debate was touched on only breifly – PULP is a cleaner more refined fuel – run on it all the time and your engine wear is reduced. This is why mechanics often recommend to non PULP users to chuck in PULP every few tanks.

  42. Many cars require 95 octane & for these 98 RON gives virtually no extra mileage (& is not cost effective), but fewer & fewer servos have 95 pumps (Shell & particularly Shell Coles are noticeably bad at getting rid of most of their 95 pumps – their website shows only a handful of 95 pumps in all Sydney). So we are forced to waste money buying 98. I have given up on Coles & am changing to servos that sell 95 as it saves far more than the discount coupons are worth.
    Additionally it is very difficult to know which pumps belong to which octane rating – usually not displayed on the pumps & the staff rarely know. In the UK all pumps have a 1->5 star rating on their pumps for instant octane recognition. I cannot understand why state/ national government Consumer Affairs don’t legislate this ‘star rating’ as compulsory here, so we can cut through all the petrol company branding & marketing to find exactly what we need for each vehicle & save us all money.

    • Regarding Humber Vogue. At one time I had 15 of them and they all ran much better on 98. More so I ran 6 of them as wedding cars and the difference was remarkable. They start smother and run smoother with noticeable better pick-up.When i pull down the engine they are not spotless but certainly very little carbon.

  43. In 2000 the Danish Environmental Protection Agencty & Consumer Affairs mounted a national campaign to reduce 98 octane petrol use because it has high MTBE which is suspected of polluting ground & drinking water. Motorists were encouraged to switch to 95 RON as this contains considerably less MTBE. 38% of motorists have switched so far & a further 25% are considering switching.
    Interestingly Danish petrol companies are restricting sales of their 98 RON petrol down to 200 petrol stations & providing lists of those stations.
    Additionally Oz petrol companies are increasing 95 & 98 premium fuel prices more than ULP prices as shown in NRMA’s new report of September 2009 (on their website).

  44. I have a 2000 BMW 323i and always use PULP. that’s what my car was designed to run on and it works perfectly. I also have a 2003 Ford Fairmont which runs on ULP and although the fuel tanks are identical in size (60litres)
    The BMW runs much smoother, and goes much further per tank. It may just be the fact its a BMW compared to a Ford but my opinion is that PULP is brilliant (for cars designed to run on this)

  45. There are some serious errors in this article, however the main one is the statement that a 1 digit increase in RON equates to a 1% increase in power and 1% decrease in fuel consumption. This is incorrect. For example LPG will (dependent on the ratio of Butane and Propane) will have a RON of between 110 and 130 and the total consumption figure for this fuel is some 30% higher than petrol on the same engine. Additionally, Ethanol has a RON of 129 and again you will need more ethanol or ethanol blended fuel to travel the same distance. At the end of the day, a fuel with a higher octane rating can be run at a higher compression ratio without detonating, ie the octane rating dictates the engine the fuel can be used in. The only measure that can be used to gauge the amount of energy that can be obtained from a fuel type is the calorific value of the fuel.

    Thanks Tony. This will be addressed and updated accordingly in the near future.

    - NRMA Motoring Blog

  46. does anyone no if it is really necessary to run a car that is said to require premium unleaded on standard unleaded petrol?
    i own a 2003 mazda 6 luxury sports but really can’t afford to keep putting in the premium unleaded. Will running it on standard unleaded cause me any major or even minor problems other than slight power & economy decrease?
    I’m also looking at upgrading to a cx-7 to replace my holden captiva, but would i be able to run the cx-7 on standard when it is said to be requiring premium unleaded?

  47. a few months ago i filled up my mothers mercedes benz s 500 with a 5.5 litre v8 using e 10 unleaded petrol and the car ran just as well as it was using 98 ron premiem unleaded fuel and it didn’t even ping right through the rev range to the red line and the car uses mobil 1 engine oil as well and also i ran 98 ron octain on a 4 stroke 115 hp mercury outboard motor and we ran it out to the red line and it didn’t ping at all and if we still had the motor now i would try e10 on it and the boat we have now had a v6 4.3 litre petrol ohv efi sterndrive and the engine is rated for 95 ron octain we have used 91 ron on it and it doesn’t rev much past 3400 rpm under load but if i tryed using 98 ron i mite take it out to about 4100 rpm the redline is 4500 rpm and i mite have to use mobil 1 oil on it

  48. Hi Jono
    I’ve got a 2.2L Mazada 6 and use 91RON fuel. Mazda recommend 95RON. Nothing has gone wrong with the car and it’s done 88,000km. I’m not a mechanic though so wouldn’t know the long term effects of doing so.

  49. I enjoyed reading the above comments. My wife’s 2002 Pug 406 3 litre V6 requires min. 95RON fuel. We havn’t noticed a lot of difference between brands except for price, which makes no sense if economy at the tank is all you are after. After travelling to Brisbane and back to Albury via Sydney i have decided that fuel prices are incredibly inconsistent. The east coast definitely has a holiday surcharge and it is based around highway petrol stations, particularly where motorists have limited choice. Because of this, it doesn’t tend to show up in NRMA fuel price watch figures which don’t include PULP prices anyway for some strange reason. On Jan. 8th, Shell were charging $1.49.9c / litre for Optimax at Thornleigh in Sydney (only servo on southbound side between freeways). I drove to Goulburn (2 hours away) and paid $1.36.9c /litre for Mobil Synergy 98 at the Big Merino highway stop. I noticed in a previous 2008 NRMA fuel pricing review it was claimed that Shell / Coles were ripping off the public, and recommending the authorities do something about it. That obviously hasn’t happened.

  50. I use 95 & 98 in my e46 325 BMW
    I find a lot of variation eg sometimes I get better fuel economy from 95 v 98 octane.
    Sometimes it is the other way around.
    I always record my fuel economy and whehre I buy fuel from.
    It is my observation that I get better fuel economy using Shell v Caltex. Mind you, this may be a placebo.

  51. My Mazda 3 MPS runs fine on E10 and averages about 9 litres per 100 kilometres driven smoothly. My Toyota Echo seems to run best on ULP, it uses slightly more E10, about 0.5 litres more per 100 klms. My Mazda MX5 runs nicely on PULP. You choose the fuel that suits your car best. Hard to get accurate comparisons because traffic keeps getting in the way.

  52. i have a 2009 ford xr5 turbo, its say to use 95 or higher, my saleman told me to use v power as its t6he best. so i did i did a trip of 320kms on it and got 9.4 as my adv, 1 step climb rest mainly flat, thought that was a bit high on the adv, so the next trip on the same route i used bp ultimate and i got 9.0 did the same route on mobil 8000 9.1 same route on votex 98 8.7 and votex 95 got 8.9 so there is a clear winner here

  53. I used 98 RON on my Toyota Prado when I do long drives. I found the engine doesn’t struggle much when negotiating uphills and also good for overtaking when you needed that extra bit of power. And for long journeys, I think it adds about 10% more mileage as well compared to using the regular 91 RON. (BTW I never use E10.)

  54. In mechanical engineering terms, the higher the Octane level the higher the HEATING VALUE therefore more energy released during combustion.
    So, if all things being equal. using petrol with higher Octane rating should give you more power or mileage.

    • There is so much more than just the amount of energy fuel has in it. You need to take into consideration combustion chamber shape, intake air temp, camshaft duration and timing as well as engine load. I have a vy v6 auto with a modified engine, just slightly different camshaft timing and more compression and a custom intake manifold. I run the car on 105 octane fuel as i find this fuel most economical on the street. It runs great and has put a few V8s in their place on the track too. Not every vehicle will respond to higher octane fuel, it is trial and error and it is definitely not a scam by the fuel companies. I say if it works for you then why not use it. if not then you have the choice.

  55. I own a Jaguar X Type and a BMW 323i. I have driven them both on 95 RON and 98 RON fuels, and for the life of me didn’t notice any difference whatsoever.

    My opinion is stick to the cheaper 95 RON fuel

  56. I have recently converted to using PULP in my 2007 Nissan X trail ST. My car was having a regular hard to start problem. I previously used regular unleaded and somtimes E10 unleaded. My Nissan service advisor told me the use of E10 has damaged my car! I was told I should only use Premium fuel to clean out my engine! The car has improved with the hard to start issue and is running alot smoother on premum fuel. I have tried all the major brands and have found BP Ultimate and Caltex Vortex to be the best. Shell V-Power is terrible, burns very quick thus mileage is low and gives me those hard to start problems!

  57. depends what you want. 95 ron is fine on most cars, i drive a mazda 6 mps and i will only use 95 ron because not all gas stations supply it. not only that you have to faff about pulling along side a pump in a station your not familiar with. mps goes like stink and you have to be damon hill to notice the differance. USE 95 RON! YOU OBSESSED PETROL HEADS!

  58. I was at the Honda dealer for a scheduled service of my 2009 Honda Accord. Happened to have a discussion with another customer about the use of premium and E10 fuel. I only use premium 98 ron fuel as I don’t like the sound of using ethanol in my vehicle. The other customer always used E10 fuel. She apparently has her car in for a warranty claim for her engine which the dealer said that the continous long-term use of E10 is harmful to the engine and most likely contributed to the problem. I wouldn’t mind using standard unleaded fuel if they offered it without the ethanol at the pump but it seems that it is not readily available. Honestly believe that the oil companies intentionally and strategically set it out this way so customers may be more inclined to buy premium fuel at the higher inflated prices.

  59. Mitsubishi Magna TH, 3.5 litres, auto trans., long term statistics.
    Standard unleaded fuel average litres/100km = 9.2
    Premium unleaded fuel average litres/100km – 7.5
    In my case, despite the price difference, it is cheaper to use more expensive fuel.

    • Sorry to be the bearer of bad news, but something is significantly off with your stats :)

      Your TH is of the third generation of magnas/veradas and therefore doesn’t have a knock sensor (and you can’t retrofit one easily either because the ECU doesn’t support it).

      Due to the absence of a knock sensor, the ECU is unable to advance ignition timing when premium (95 or 98 RON) fuel is used so you get zero increase in power/torque and no better fuel economy than regular unleaded (91 RON).

      I’m afraid the only effect of using premium in your TH is going to be on your bank statement (or if you believe the hype, premium has better detergents and so cleans your engine).

      Interestingly though, the second generation magnas/veradas did have a knock sensor — it’s a shame MMAL decided the 3rd gens didn’t need one!

      Your stats may reflect other factors that changed (ie: different drivers & driving styles, short vs long trips, highway driving vs urban stop/start, different tyres & rims, tyre pressure, uphill driving vs flat or downhill coasting, tune-up or service of the car — have the injectors been cleaned, if you changed any exhaust components etc..)

  60. My chariot is an ex-CFA “chaser”: 2006 Commodore VZ wagon with 175/V6 engine. Prior to delivery and the first couple of weeks, I noted the exhaust pipe, during cursory inspection, was filthy — black and sooty: attributed to short duration trips when cold rather than long, high speed driving. That time was 5,600km ago. Since that time I have been running PULP95/98 (98 where I can find it) to “spring clean” the engine. Holden Alloytec 190 will benefit from this, as too, will the “baby brother” 175. Techies have confirmed PULP98 offers cleaning benefit at freeway speed on long runs (and I do a lot of freeway driving); the trips just get better and better over time. With 89,320km done, economy at freeway speeds is a good 7.8L/100km, rising to 9.7L/100 with 3 adults and rucksacks plus sundry camping/bushwalking gear. The car is noticeably sprightly on take off (with transmission in Normal, not Power mode) and does not struggle anywhere on hills (actually need the binders on for most hill country driving). Tank-to-fill (not a long range option) is 770km. And the exhaust pipe? So clean you could eat a sandwich off it. So, I do not use ULP91 as it does not seem to provide any power efficiency vs PULP98 and given I come from the country (now in the city) the extra few cents for PULP98 does not concern me for the benefits derived.

  61. To r hill we not in the U.S. and so refer to car fuel as “petrol”. What we call “gas” is, well, gas (petrol is liquid).
    Now, I have an old (1968) Valiant which runs dual fuel (petrol and gas), and I discovered that gas is about 110 octane. This essentially means that I could advance the ignition quite a bit. Problem of course would then be the petrol: If I only ever use 98 octane petrol I can safely advance the ignition by 5 degrees (which I did). If I didn’t use the 98, I’d get detonation problems on petrol. The 98 also seems to just run the car better. On the freeway the car is noticeably more responsive than with 91 did at the standard ignition setting. The improvement in acceleration can’t really be felt, but the speedometer definitely climbs more quickly than it did. Additionally, the car seems smoother.
    So convinced about the benefits of 98 RON that my new car (’96 Verada) will only ever be given this fuel. Knock sensors take care of any ignition timing errors, and I just set it at 12BTDC (advanced by 7).

  62. I used PULP in my 2007 Ford Focus zetec on a day trip to Canberra from Camden.
    Set cruise control to 100kph and attained 40.03mpg. But little or no difference for
    local driving between work/shops etc.

  63. I use e10 and PULP in my Tarago. The use of ULP makes the vehicle run ruff. The best is PULP where it is quiter, more fuel efficient and when loaded up with 5 adults and luggage doesn’t labour as much normal trips I get 11l/100km PULP and 12.5 /100 E10 so it just depends on the pump difference between the 2 fuels which one I choose except for long trips where I use PULP

  64. I have a 94 ford xlt and I use pulp and the car drives way better and longer on one tank of gas only down fall is theres a weird smell wen fuel gets low but its a sweet smell so not that bad

    • I would use 95 octain or 98 but don’t touch e – 10 but check with your mechanic first but they mite adjust the timing for 95 or higher. I know someone that had volvo 740 converted lp gas and he had to get the timing adjusted for lp gas but it would ping on petrol but it is amazing how many people put regular unleaded into europeien cars and the lowest octain is 95 because they don’t have 91 octain in europe and there are japanese cars in europe and you would be better off using 95 octain and even japan as higher octain unleaded then 91 octain and i had a 1997 manual toyota prado and i only used 95 octain unleaded and i did 148,000 km in it and i had it since new and if i used 91 octain it was slugished and i used shell semi synthetic engine oil 15w40 in it and the compression was perficed until i traded it in for another 4wd

  65. What I see in the comments is a lack of understanding of cars. Some very basic models will never get any better performance or economy between 91, 95 or 98. Simply because the engine management cannot make use of better fuel. The only thing is you will be putting (slightly) less pollutants into the atmosphere. Have a performance engine??… and in many instances you really must use 95 or 98. I have a modern Turbo and an old Falcon v8. Both only ever get 98. The v8 pings terribly and has less power on anything but 98, it’s a must. The turbo can do with 95 but 98 is the best. the engine management system in the turbo “learns” as you drive and can work better with higher octane fuel. It’s impossible to test the different octanes side by side as conditions continually change… air temp, humidity, condition of your spark plugs, head winds, tail winds just to name a few things. Put simply, if you can feel, hear, measure a difference, use high octane. Its better for your engine and the environment. I’d like to see a tax break for higher octane fuels seen as they are “greener”.

  66. I have a 1996 holden barina SB swing with the C14NZ 1.4L single point throttle body injection because of the type of motor it has an octane coding plug which meens that when i use 91 ulp i have the switch set to 91 and when using 95 pulp i have it switched to 95. now when i am running 91 ulp in-order for me to sit on 40km/h I have to sit in 2nd gear flat to the floor in-order to do that not why not go 3rd well here is the thing i go into 3rd and the engine starts surging which meens there is not enough power to do that speed. sounds stupid but guess what when i run caltex vortex 95 i can sit on 40km/h in 3rd just touching the throttle. to me that means a very noticeable increase in power. i have noticed that I now have more low end torque in this tini low powered motor. now to fuel efficiency ulp in my engine got very poor fuel economy round 8L/100km hwy but running pulp in this little motor 4L/100km hwy and in terms of engine running noises slightly quieter and smoother running pulp over ulp. but this is my experience in this car yours may differ because this motor is tuned to run on both 91 and 95 so i can benefit from the higher octane with the octane coding plug

  67. I’ve had a ’96 Hilux tray-back ute (22R motor) for over 10 years now. I’ve been driving it mostly over the mountains between Grafton and Armidale NSW and found that 98 not only gave the little donk more grunt than 92, it gave better economy as well (about 6%) I am about to buy a 2002 vx ss 5.7ltr 6 speed and will be running 98 in it. I could be wrong but I believe the extra cost at the pump will be offset by better economy and a better engine life. Oh, my 2009 Harley Davidson will run on 92 but much prefers 98

  68. I think it’s about time that we stated the calorific values of fuels as well as the Octane rating. Rating fuels only according to the Octane rating gives a false impression that a fuel will “perform” better in terms of power output and possibly fuel consumption. While that is often the case the effect is not because of the Octane Rating (unless the engine is designed for a higher Octane fuel – higher compression, slower burn) but because of the increased calorific value of the fuel and additives that can “help” the engine. It’s entirely possible to have a low Octane fuel with a high calorific value.

  69. My Renault Laguna V6 needs Premium, but I’m curious to know the benefit of 98 over 95.
    I’ve been advised that 98 is more for high-performance motors, and not necessary for “daily driving” . Any advice on the difference / benefit between the two RON ?

  70. Premium unleaded is a big con, the oil companies are laughing all the way to the bank at your nieve expense, the octane levels an so small in difference from regular unleaded it don’t make a damn difference it’s all in your head, only pure ethanol gives you extra power lol

    • More power but you need three times as much fuel. Premium fuels are not a con. Performance and economy gains are vehicle specific. If it doesn’t work for you then simply don’t use it!

  71. hello iam using bmw 750li in saudia arabia and i exported from usa i have query which tyoe of petrl should i use her in( saudia arabia ) only 91 and 95 are available here so pls tell me

  72. My partner just put Mobil’s 98 unleaded in his 1966 Ford Falcon and it has been running horribly. I just read that he may require an anti-valve seat recession additive. Ah I knew he should have just gone to Shell and got 95…

  73. what if you use higher octane than your required octane requirement of your car is it good?
    its all base in comp ratio if its too high octane nothing beneficial will give to you
    and it cost more than you ever think

  74. Hi,
    I’m running a 2004 VZ Berlina I used to use unleaded which I was getting pretty good consumption out of. But then I started to just use 98 it made an improvement in fuel. Then after a month or so after all the crap was cleaned out of the engine I noticed a big difference in better fuel consumption and power.

  75. I have always used unleaded in my 1994 Honda Civic until recently. My grandson has filled it up with Premium Unleaded. He says it will run better and I will not need to replace my exhaust every two years as happens now. The car is not used often and mainly for short trips around the local area. Should I continue to use PU..

    • Hi Marg

      Use whatever is recommended in the owner’s manual – the vehicle will not benefit from using a higher octane fuel than recommended. Exhaust systems rusting out was only an issue with leaded petrol, which had acidic scavengers in it, so you wouldn’t expect any benefit in exhaust life from using premium rather than standard petrol.



  76. Hi

    I have just bought new Honda civic 1.8 2011 model.

    I can see bit less fuel efficiency in city drive 10l/100 KMs

    I always use Vortex 95.

    Does it sounds fuel issue?

    • Hi Bhaumik

      The city/combined consumption for the 2012 Civic VTI auto (MY11) is 7.2 litres/100km, consumption tested under laboratory conditions, using standard ulp, to ADR specifications, for comparison purposes between models.

      The actual consumption may be higher depending on driving and other conditions. You should not depend on the vehicle’s computer to measure fuel consumption – record your own tank fills and distances driven to calculate fuel consumption.



      • Thanks Jack for prompt response.

        I have checked my self with records (tank full to tank full)

        its around 40 litres per 420 kilometers with vortex 95.

        I feel its less than expected, needed your expert opinion

        • The official figures are conducted on a dynamometer at around 24 deg C and the manufacturers prepare the vehicles carefully to obtain the minimum fuel consumption. The consumption of your vehicle is within the range expected when comparing with these figures.

  77. Is it okay to mix fuels? For example, to fill up with half 91, and half 98 (or 95)? Or half E10 and half 98?
    If so, would it be worth it? The only reason I’d use half 98 is because it has extra additives (at some servos) that clean your engine and so forth.

    • Hi Graham

      No problem to blend fuels as long as 1) you only blend ethanol in a vehicle suitable for ethanol and 2) the octane you end up with is high enough for your vehicle. You can roughly calculate octane by the proportion of the two, so 50/50 91 and 98 should end up around 94-95 (so if your vehicle requires 95 you might be marginally under what is required). All petrol has detergent in it and NRMA has no reports of engine deposits being an issue. It is unlikely that blending different octane fuels is economically advantageous.

      Best regards


  78. 1- i have caprice 1994 i used 95 for long time i thought i get more power and save fuel now my question can change to 91 and i don harm my engine
    2- i used company car toyota 2013 pickup i fill tank with 95 but i changed to
    91 i noticed. the hilux pickup save gas than when i used 95
    thanks for website its helpfull
    on fuel tank of high lux it written unleaded only but all gas are unleaded
    aprice 1994 v8 4.3l always fill 95 in tank i thought this will give
    the which number must i choose

  79. We have a 2010 Mazda CX-9. Whilst the vehicle is supposedly mean’t to be able to run on E10 fuel when we tried it we had some of the lights in the dash come on. Upon contacting our Mazda service dept they informed me that the electronics didn’t like the lower grade fuel mixes. I filled up the next tank with 98 and everything returned to normal. If I remember correctly they said we shouldn’t use anything less than 92, which rules out regular unleaded also. The car definitely runs better on a premium fuel.

  80. I use premuim and I can’t understand why it has gone up from 4 cents dearer to 19 cents I don’t understand I’m fairly sure the ingredients haven’t changed.

  81. When I owned an MGB it was sluggish with initial startup & driving on 91.
    With 95 it had the “get up I want to go” attitude.
    With the now Porsche 911 SC I use 95 and occasionally go to 98 for a bit extra grunt

  82. What the doubters seem to forget before unleaded came is there were only two grades/ octaves. Regular and Super. Regular was 91 and Super was 98. Every car on the road used Super and we used Regular in our mowers and simple engines. There was always the understanding and appreciation that Super was always used in car engines, for better performance and mileage. I believe there are too many different grades/octaves. Therefore increased costs due to different manufacturing requirements. Give us back 95 and 98 and be done with it…!

  83. I can’t speak for anyone else, but i’ve had an ’03 VY 2 as my daily drive for 10 years… Since I’ve owned it I’ve put nothing in my cars’ tank **EXCEPT** E10…

    Haven’t had a problem yet & the car regularly returns economy figures at 10 – 10.3 litres per 100km when the factory rating says 11…

    In fact I’ve had worse performance from my car when I put non ethanol petrol in the tank… I hate regular unleaded; 91 or 98 doesn’t matter.

    Most cars can take E10 if they can use unleaded… The key is that Ethanol fuels require better quality rubbers & carburettor seals in the fuel systems. Other than that, the trend back to ethanol blends is a good idea now the technology to mix them & to have engines burn them has improved…

    How many people on this thread realise that the earliest fuels used in early cars, at the start of the motor vehicles’ existence were ethanol blends?

    The reason cars sputtered is because the engines weren’t able to burn it properly, so the ethanol was phased out & other additives put in… Like lead.

  84. Pingback: What have you done since petrol prices dropped? | The NRMA Blog

  85. Your very own dedication to providing this article became extraordinarily helpful.

  86. Hi everyone
    My 2014 Hyundai i30 was hesitating when merging onto the motorway at between 60 and 80 km/hr. Before booking the car in for an inspection , the Hyundai rep. asked what octane fuel I was using and said to try switching from 91 to 95 octane. The problem was solved and the $150 dollar inspection fee I saved will cover the higher pump price for the next 12 months. This ignores any improvement in fuel consumption and/or performance.
    I decided to pursue this further and received the following comments from members of the motor trade;
    “91 octane is c#%p, I would not use it in my lawnmower”
    “91 octane is bad for the customer but good for me based on the amount of money I make replacing blocked fuel filters and cleaning dirty injectors”
    I suppose getting a definitive answer on which octane rating is better suited to the modern petrol engine is too big an ask.

  87. It is about time that tests were done on all car models to prove the efficiency and cost saving for all types of fuel. Why isn’t it done? People are being prevented from knowing the real truth. The whole ethanol move is a lie! Do you really think adding 10 per cent ethanol to dirty oil fuel makes any major different to carbon dioxide pollution? Come on now. Any idiot can see that it has no significant effect at all. It is like adding 10 per cent water to your beer then complaining to the police at the RBT. It hardly has any effect at all.

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