Top green cars

While downsizing your car, or changing to a newer, more efficient model is an obvious way to save money on fuel, it's also a small but significant step towards saving the planet as well.

Global warming is caused by an excess of carbon dioxide in the atmosphere. Every litre of petrol that goes through your engine releases approximately 2.3 kilograms of carbon dioxide from the exhaust. Cars and trucks together account for about 13 per cent of total carbon dioxide emissions.

Motor vehicles are also the most significant non industrial contributors to air pollution, according to the 2004-2005 National Pollution Inventory report. Diesels produce relatively high particulate and nitrogen oxide emissions. Carbon monoxide, benzene and other organic compounds contribute to smog and health problems.

The European Commission's recent announcement that it wants to reduce carbon dioxide emissions from new cars to a maximum of 130 grams per kilometre by 2012, drew howls of protest from the car industry. It also aroused the ire of the Greens, who, equally predictably, claimed the new measures are not tough enough.

The proposed new EC rules follow the failure of car makers to meet the voluntary 140 grams/kilometre target by 2008, set nine years ago by the Commission.

Most new cars sold in Australia don't come within coo-ee of either target, according to data published on the federal government's Green Vehicle Guide website.

In fact only two cars - the Honda Civic and Toyota Prius hybrids - beat the proposed 130 grams/kilometre EC target. The Honda produces 109 grams/km; the Prius produces only 106 grams/km. The Holden Commodore Omega produces 260 grams/km. The Ford Falcon XT produces 255 grams.

So the chances of the local car industry urging the federal government to go clean and green by adopting the proposed EC emissions target are, shall we say, slim.

Big, heavy petrol powered 4WDs are the worst offenders. The Nissan Patrol 4.8 litre automatic, for example, dumps 408 grams of CO2 into the atmosphere for every kilometre it travels.

The Green Vehicle Guide is the place to go if environmental considerations are an important factor in your new car purchase.

It lists the specific amount of CO2 produced by each model, and includes this as part of a "Greenhouse rating." It also gives each model an Air Pollution Rating, and combines these, plus average fuel consumption, for an overall star rating, out of five.

The 15 cars at the top of the table are a diverse bunch, but there are no diesels. While diesels top the fuel consumption charts, and as a consequence produce lower carbon dioxide emissions, their relatively poor showing in the Air Pollution Rating table adversely affects their overall score.

Toyota's Prius leads the top performers with a five star rating; the Fiat Punto, Citroen C3 and Mercedes A150 also score five stars.

Four and a half stars go to the Holden Astra, Honda Civic/Civic Hybrid, Mercedes A200/B200, Saab 9-3 Linear, Toyota Corolla, Lexus RX400h and GS450h hybrids, the Lotus Elise and the smart fortwo.

Let's look at a few of these green machines in detail.

Toyota Prius from $37,400

If the EC adopts the 130 grams/km target, the age of the hybrid will have arrived.

A full size family car with five star safety, blue chip Japanese quality, all the gear you need and a consumption rate (measured by us) of only 5.6 litres/100 km - on regular unleaded - in city traffic? The Prius proves it is possible.

Its Australian test standard average consumption is 4.4 litres/100 km; its CO2 emissions are 106 grams/km.

The 1.5 litre petrol engine/electric motor/battery hybrid drivetrain shifts the Prius from rest to 100 km/h in 11.6 seconds - comparable with a Corolla.

Fiat Punto from $19,990

The specific Punto model which scores five stars is the 1.4 litre petrol version, which we haven't yet driven. However, with only 57kW of power, we can guarantee that you'll have plenty of drive time to feel good about your minimal contribution to climate change.

The Punto is one of the best handling small cars around, though, and quite spacious by class standards as well.

Fiat dealers are including on road costs and a $599 portable satellite navigation system on the Punto 1.4 until the end of March.
Standard equipment includes six airbags, cruise control, air conditioning and ABS brakes.

Average consumption is 5.7-5.9 litres/100 km, using premium unleaded, CO2 emissions are 134-140 grams/km.

Citroen C3 from $17,990

The 1.4 litre and 1.6 litre versions both score well, with the newer 1.6 just shading the smaller engine (which scores four stars) due to its cleaner technology and better Air Pollution rating.

The C3 is one of the cutest things on four wheels, but like the Fiat the 1.4 litre engine is not petrolhead material. The 80kW 1.6, which starts at $21,990, is worth the extra spend.

It's also available with a four speed automatic.

Ride and handling were improved at the car's most recent upgrade, when the 1.6 was introduced. Back seat space is tight.

Six airbags, ABS brakes and airconditioning are standard; the 1.6 adds alloy wheels and velour upholstery.

Average consumption (1.4/1.6) is 6.2/6.4 litres/100 km; CO2 emissions are 148 grams/km for both variants.

Mercedes A and B Class from $29,990

We looked at the A Class last week and recommended the 85 kW 1.7 litre A170 over this base model, by virtue of its stronger performance and better overall value for money.

However its the 70kW 1.5 and the higher spec 100kW 2.0 litre A200 (from $40,400) that score highly in the environmental stakes.

The 1.5 earns five stars, with an average fuel consumption of 6.7 litres/100 km and CO2 emissions of 159 grams/km. It's a bare bones equipment list for $30,000, with steel wheels, manual only, and a single CD player. However, the A Class is also a five star NCAP crash test scorer.

The A200 averages 7.4 litres/100 km and emits 177 grams of CO2 for each kilometre travelled.

As does the larger B200, (from $44,900) which is worth test driving back to back with a Prius if you're looking for safe, practical, versatile family transport.

The B200 is well quipped, with cruise control, rain sensing wipers, six airbags and a tyre pressure loss warning system. Generous back seat and load space and a five star NCAP score add to its kid carrier credentials.

Holden Astra from $23,990

The 90kW 1.8 litre petrol manual variant scores top billing in the Green Vehicle Guide's overall ratings, using 7.4 litres/100 km and producing 177 grams of CO2/km.

It's available as a coupe or five door hatch.

The latter is great value at present, with a $22,990 driveaway deal on the base model CD manual. Standard equipment includes four airbags, ABS brakes and a CD player; the deal adds alloy wheels, cruise control and power windows, until February 28.

The Astra is one of the better drives in the crowded small-medium field. It has plenty of space for four adults and their gear, excellent ride and handling, and a secure, solid feeling on the road.

The 1.8 is a slugger, but its also refined and tractable.

Lexus RX400h from $94,100

Like the Prius, the Lexus RX400h hybrid 4WD shows that hybrid technology can and does work in the context of day to day vehicle usage. It's not weird, just very clever.

The Lexus uses a 3.3 litre V6 petrol engine/generator/high voltage battery as its power supply, individually or functioning together via a planetary gearset. Its power output is rated at 203kW.

Put your foot down and the Lexus really moves. Electric motors produce maximum torque from startup, so the hybrid is just as quick, and arguably more responsive than its RX350 petrol counterpart.
 
In Sydney traffic, we recorded just 9 litres/100 km, comparable with a 1.6-1.8 litre small car. This from a wagon that weighs nearly two tonnes.

The Australian standard average is 8.1 litres/100km, and CO2 emissions are 192 grams/km.

By Bill McKinnon, March 2007.