Fuel strategies
Fuel strategies
It's now a long time since you could buy a litre of unleaded petrol for less than a dollar.
Prices continue to rise and fall, of course, but if you're expecting a return anytime soon to the days of seventy or eighty something cents per litre you're likely to be extremely disappointed.
As an added bonus, you'll also be minimising your contribution to global warming. Every litre of fuel your car burns costs you more than cash - it also produces 2.3kg of carbon dioxide, the main greenhouse gas.
Step one is to calculate how much fuel your car actually uses. You'll then be able to assess the effect of any change to your driving habits or fuel choice.
It's easy to work out your car's fuel consumption.
In the longer term, neglect compromises durability and reliability, which leads to expensive repair bills and a lower trade-in price.
You should get your car serviced at the intervals specified in the manufacturer's handbook. If you don't have one of these, email NRMA's experts or call 1300 655 443 and they'll be able to give you the information you need.
It's also worth noting that today's lighter viscosity oils not only protect your car's engine more effectively than the old monogrades and 20W 50 staples of years past, but they can also produce fuel economy gains.
Ford specifies an SAE 5W30 engine oil for the AU and BF Falcons for this very reason. Check with your mechanic, or dealer, if a light viscosity oil is suitable for your car.
Under inflated tyres create more friction with the road surface, which can also increase fuel consumption by up to ten per cent. Low pressures also increase heat build-up in tyres, leading to premature wear and increasing the risk of tyre failure - a blowout.
Tyre pressures should, as the minimum, be set at the manufacturer's recommended levels, again found in the handbook or on a sticker somewhere on the car itself - usually on a front door, the door frame or the inside of the glovebox lid.
Check and set your car's tyre pressures once a week, with your own pressure gauge. These cost only a few dollars and are much more accurate than the ones on service station forecourts.
If you're unsure as to the correct pressures, again email NRMA's experts or call 1300 655 443.
Light cars use less fuel than heavy ones, so if you use your car's boot as a storeroom, clean it out.
While you would have to be a masochist to endure an Australian summer without airconditioning in your car, ask yourself if it's really necessary all the time. In winter, your car's heater will work perfectly well without the airconditioning switched on.
On the highway, it's actually preferable to use airconditioning rather than open all the windows. At highway speeds, this just creates more aerodynamic drag compared with having the windows closed; this can increase consumption by up to 20 per cent. Roof racks also significantly increase drag and fuel consumption; take them off when you're not using them.
OK, that's the car side of things taken care of. What about your driving habits.
How you drive can make a big difference to your car's fuel consumption, especially if it's a large sedan, wagon or 4WD with a six-cylinder or V8 engine.
The trick to getting reasonable economy in the city is to keep your car rolling, which means anticipating changes to the traffic in front of you, making your moves early, and treating the brake and accelerator with tenderness.
It's shifting the mass from rest that uses the most fuel, especially in big cars, so the less stop/starts you have to do, the more your economy will improve.
Turn the engine off if you're going nowhere in a hurry - idling with the transmission in gear actually uses more fuel than normal driving.
The other simple fuel saving technique is to take it easy on the accelerator. More revs equals more petrol. It's easy to go with the traffic flow in a Falcon, Commodore or large 4WD with the tachometer barely registering more than 2500 rpm. Even a 2.0 four cylinder engine doesn't have to be thrashed to perform adequately in suburban driving.
That said, lugging an engine - using too few revs - can damage it, so don't use too high a gear either.
Now we come to the vexed issue of what type of petrol you should use.
As a general rule, if your car is designed to run on premium unleaded - 95 or 98 octane - you should use it. Premium is recommended for some cars but the manufacturers also state that regular unleaded - 91 octane - can safely be used.
If that's the case, based on our experience, you can expect slightly less performance - in most cases unnoticeable - and fractionally higher consumption.
However, if the manufacturer's handbook recommends 91 octane - regular unleaded - then you're probably wasting your money on the more expensive stuff.
The best way to sort this one out is to do your own cost/benefit analysis. Run a couple of tanks of both fuels through your car, see for yourself if there's any performance gain, and work out the difference according to the consumption formula.
Keeping your car running well, driving with a light touch and choosing the right type of petrol will save you serious money on your fuel bills. You might still have to pay $1.35 or so per litre, but you can also drive that $1.35 further.
Article by Bill McKinnon, February 2006.
Prices continue to rise and fall, of course, but if you're expecting a return anytime soon to the days of seventy or eighty something cents per litre you're likely to be extremely disappointed.
So how can you keep your petrol bills under control in a $1.35 per litre world?
You can reduce your car's fuel consumption, and save money, by making sure you choose the right type of fuel, keeping your car in shape and adopting smooth driving techniques.As an added bonus, you'll also be minimising your contribution to global warming. Every litre of fuel your car burns costs you more than cash - it also produces 2.3kg of carbon dioxide, the main greenhouse gas.
Step one is to calculate how much fuel your car actually uses. You'll then be able to assess the effect of any change to your driving habits or fuel choice.
It's easy to work out your car's fuel consumption.
- Next time you fill up, wait for the nozzle to click and stop pumping fuel into your car's tank
- Then give it a few seconds for the fuel to settle, and top the tank up until the nozzle clicks again
- The shape of some fuel tanks and filler necks sometimes means that the tank will take another litre or two, after the nozzle clicks off the first time, before it's actually full
- Use this procedure while you're doing your consumption calculations and they'll be accurate, because your tank will always be filled to the same level each time. Don't, however, overfill it to the point where petrol is visible in the filler neck itself.
There's no need to note how many litres the tank takes at this stage.
- Set your car's trip meter to zero, and go about your normal driving routine
- Next time you fill up, record how many litres your car has used and divide this by the distance shown on your tripmeter, for a consumption figure expressed in litres per 100 km, the standard quoted in Australia.
Here's an example: Your car's tank takes 46.8 litres when you fill it up. The tripmeter shows 365 kilometres. Divide the kilometres driven by 100, to get, in this case, 3.65. Then divide the litres used by this number -- so here the calculation is 46.8 divided by 3.65 -- and you get a consumption rate of 12.8 litres per 100 kilometres.
The aim is to get that rate down.
Car servicing
How long is it since you had you car serviced? It is false economy to neglect servicing. In the short term, your car uses more fuel than it should - ten per cent or more if it's running roughly.In the longer term, neglect compromises durability and reliability, which leads to expensive repair bills and a lower trade-in price.
You should get your car serviced at the intervals specified in the manufacturer's handbook. If you don't have one of these, email NRMA's experts or call 1300 655 443 and they'll be able to give you the information you need.
It's also worth noting that today's lighter viscosity oils not only protect your car's engine more effectively than the old monogrades and 20W 50 staples of years past, but they can also produce fuel economy gains.
Ford specifies an SAE 5W30 engine oil for the AU and BF Falcons for this very reason. Check with your mechanic, or dealer, if a light viscosity oil is suitable for your car.
Under inflated tyres create more friction with the road surface, which can also increase fuel consumption by up to ten per cent. Low pressures also increase heat build-up in tyres, leading to premature wear and increasing the risk of tyre failure - a blowout.
Tyre pressures should, as the minimum, be set at the manufacturer's recommended levels, again found in the handbook or on a sticker somewhere on the car itself - usually on a front door, the door frame or the inside of the glovebox lid.
Check and set your car's tyre pressures once a week, with your own pressure gauge. These cost only a few dollars and are much more accurate than the ones on service station forecourts.
If you're unsure as to the correct pressures, again email NRMA's experts or call 1300 655 443.
Light cars use less fuel than heavy ones, so if you use your car's boot as a storeroom, clean it out.
The less weight you carry, the less fuel your car will use.
Switch the airconditioning on and you can add up to another ten per cent to your fuel bill, especially in city driving.While you would have to be a masochist to endure an Australian summer without airconditioning in your car, ask yourself if it's really necessary all the time. In winter, your car's heater will work perfectly well without the airconditioning switched on.
On the highway, it's actually preferable to use airconditioning rather than open all the windows. At highway speeds, this just creates more aerodynamic drag compared with having the windows closed; this can increase consumption by up to 20 per cent. Roof racks also significantly increase drag and fuel consumption; take them off when you're not using them.
OK, that's the car side of things taken care of. What about your driving habits.
Driving habits
Firstly, modern cars - or, more accurately, modern oils -- do not need to be warmed up in the morning. Just start the car and drive away. Obviously, you don't use all the available revs until the engine reaches operating temperature, but otherwise all you do when warming a car up is waste a lot of petrol.How you drive can make a big difference to your car's fuel consumption, especially if it's a large sedan, wagon or 4WD with a six-cylinder or V8 engine.
The trick to getting reasonable economy in the city is to keep your car rolling, which means anticipating changes to the traffic in front of you, making your moves early, and treating the brake and accelerator with tenderness.
It's shifting the mass from rest that uses the most fuel, especially in big cars, so the less stop/starts you have to do, the more your economy will improve.
When you're stuck in traffic, shift into neutral - auto or manual
Turn the engine off if you're going nowhere in a hurry - idling with the transmission in gear actually uses more fuel than normal driving.
The other simple fuel saving technique is to take it easy on the accelerator. More revs equals more petrol. It's easy to go with the traffic flow in a Falcon, Commodore or large 4WD with the tachometer barely registering more than 2500 rpm. Even a 2.0 four cylinder engine doesn't have to be thrashed to perform adequately in suburban driving.
That said, lugging an engine - using too few revs - can damage it, so don't use too high a gear either.
Now we come to the vexed issue of what type of petrol you should use.
What type of petrol?
Is premium unleaded worth the extra cost - ten cents per litre or more - for the claimed economy and performance gains it delivers?As a general rule, if your car is designed to run on premium unleaded - 95 or 98 octane - you should use it. Premium is recommended for some cars but the manufacturers also state that regular unleaded - 91 octane - can safely be used.
If that's the case, based on our experience, you can expect slightly less performance - in most cases unnoticeable - and fractionally higher consumption.
However, if the manufacturer's handbook recommends 91 octane - regular unleaded - then you're probably wasting your money on the more expensive stuff.
The best way to sort this one out is to do your own cost/benefit analysis. Run a couple of tanks of both fuels through your car, see for yourself if there's any performance gain, and work out the difference according to the consumption formula.
Keeping your car running well, driving with a light touch and choosing the right type of petrol will save you serious money on your fuel bills. You might still have to pay $1.35 or so per litre, but you can also drive that $1.35 further.
Article by Bill McKinnon, February 2006.
Tool box
Font size:
