Car makers – who’s the greenest?

In the US or Japan, a common answer to the question of who makes the greenest car is Toyota, thanks to its high-profile 105g/km CO₂ Prius. But in Europe, where fuel economy expectations are higher, you are as likely to hear the names VW, Citroën, or Fiat. And given that Toyota’s few other hybrids are large and powerful, in general its cars compare badly with those of European manufacturers.

If investment in future low-carbon technologies are taken into account, Toyota, the world’s largest car maker, does better: it will have hybrids across its entire range by 2020, and by then expects to be marketing fuel-cell cars commercially. Even back in 2003, a study on the impact of climate change to the global competitiveness of nine car makers (www.sam-group.com/changingdrivers) said Toyota was best placed to take advantage of new opportunities.

Also investing heavily in fuel cells is Honda, a car maker singled out for praise by the US Union of Concerned Scientists (and one of ClimateChangeCorp.com’s top 20 climate-friendly companies). Indeed, Greenercars.org, part of the American Council for an Energy Efficient Economy, says the greenest 2007-model vehicle is Honda’s natural gas-powered Civic GX with Toyota’s Prius and Honda’s Civic Hybrid coming second and third.

Nonetheless, for the moment it is European cars that lead the pack overall.

A recent study by European green lobby group Transport & Environment (T&E) found that three-quarters of the 20 major brands sold in the EU in 2005 had failed to improve fuel efficiency since 1997 at the rate needed to meet their own voluntary target of 140g/km by 2008 – a fact which has prompted the EU to propose a statutory limit of 130g/km for new cars from 2012.


Percentage of voluntary EU-market 140g/km CO₂ emissions target to be reached by
top 20 car brands by 2008/9 on present trends



Source: Transport & Environment, Regulating fuel efficiency of new cars, January 2007


Fiat was 2006’s best performer on whole-fleet tailpipe CO₂ emissions in Europe, followed by Citroën, Renault, Ford and Peugeot. Those top five brands were on track to meet or even exceed next year’s 140/km target, and could meet the 2012 130g/km limit with relatively little difficulty.

As for Toyota, the T&E study showed that its few, premium-priced hybrids made little impact on overall performance. Besides, to European eyes – or at least in the view of Guido Reinking, editor of Automobilwoche: “There is no more ineffective or expensive method of cutting emissions than by combining a gasoline engine and an electric motor to power a vehicle.” This is because electric motors add complexity, weight and cost, and because gasoline engines emit about 20% more CO₂ than diesel engines of the same power.


"The global growth of car ownership – and peak oil, maybe in a decade or less – will demand radically lower CO₂ emissions than an average 140g/km or even 130g/km"


There are two factors behind these EU rankings: average vehicle size (Fiat specialises in small cars); and the penetration of diesel engines among the leading brands. The Japanese and Koreans caught on to diesel late, due to a lack of demand in their home markets.


Tomorrow’s heroes

The global growth of car ownership – and peak oil, maybe in a decade or less – will demand radically lower CO₂ emissions than an average 140g/km or even 130g/km, so car companies should also be judged on how they plan to reduce future emissions.

In the medium term of five to ten years, fuel-saving technologies being launched by PSA Peugeot Citroën and German manufacturers look promising. Meanwhile, Toyota expects its Hybrid Synergy Drive to become its standard offering over the next 12 years, while plug-in hybrids taking power from the grid may shift much of its customers’ emissions back to electricity generators.

But betting on the future green automotive champions involves long odds, with a plethora of new technologies now in development, including several hydrogen fuel-cell systems at the early research stage. In Europe alone, the auto industry is the biggest R&D investor of all industrial sectors with annual expenditure of around €20bn – about half of which may contribute to emissions reduction. Also developing new carbon-saving technologies are a host of suppliers, small and large; unsung heroes such as Bosch, Valeo and Denso.

Among the potentially greenest manufacturers is, perhaps surprisingly, General Motors, which ranks low in the US for its reliance on large, thirsty SUVs, but much better globally, and is a major investor in fuel cell and electric drive technology. Greening GM’s once world-beating volume of sales, now second only to Toyota’s, even modestly would do much more good for the planet than an elegant but expensive niche solution from a specialist low-volume manufacturer.

At the other end of the scale is India’s Tata Motors, still small in global terms but ambitious. It’s planning to tempt Indian two-wheeler users in mid-2008 with a car using a diesel engine of just 30hp (the same output as the legendary Citroën 2CV, but with much lower CO₂ emissions). Tata’s Rs 1-lakh (£1,250) car could transport four passengers with per capita emissions around half those of its nearest European or Japanese rivals, and at less than half the price. But for the moment, the wraps are still tight on Tata’s little wonder.

Should you care how your car is built?

It certainly counts. The average car’s CO₂ emissions from manufacture and disposal could account for up to 10% of its emissions, according to CNW Marketing Research Inc. Plants using on-site renewable energy – wind farms, as in Nissan’s Sunderland plant; Ford’s UK diesel engine plant; or GM’s planned solar-powered service and parts warehouse in California – all help. Conversely, using non-renewable minerals and energy to build complex hybrid cars with multiple batteries does not.

However, with 30-plus suppliers and hundreds of sub-suppliers contributing 70-80% of the ex-works value of a car, calculating total manufacturing emissions may not be worth the expense, and trivial compared to the impact of reducing a vehicle’s lifetime emissions.

It’s the best model at the time that counts

Less than half of consumers buy the same brand of car each time, and since no one car maker has the latest and best technology across its range at any one time, consumers increasingly make model-by-model choices. The independent www.cleangreencars.co.uk, gives maximum five-star ratings to 43 of 90 cars in different model categories, all emitting under 150g/km of CO₂.

Let no-one but ambulance drivers kid themselves that they’re saving the world with the car they buy, though. As an official of Norway’s consumer ombudsman recently ruled when banning green claims in car advertising: “Cars cannot do anything good for the environment except less damage than others."

Ultimately, there can be no finishing line in the race to be the greenest or “least-worst” car maker until we finally run out of gas. Only one thing seems certain – we can expect the current green league tables to be overturned in the next, fastest-ever laps in the race to bring better technologies to market.