One of the enemies to the reduction of emission is weight. Although car makers have been improving powertrain efficiency noticeably in recent years, a large part of the gain is offset by the increased size and weight of the cars. Car makers know this, of course, but to be competitive they have to make their cars roomier, stronger, quieter, insulate vibration and harshness better and offer more luxury, safety and infotainment equipment than ever. In 10 years time, our cars gained around 15 percent in weight.

Apparently, facing the great challenge of emission reduction, our next generation cars have to be smaller and lighter. Consumers have to be told the fact that we cannot increase interior room forever. Somehow a compromise between accommodation and fuel economy has to be made. Just like when the world was hit by Energy Crisis in the 1970s, people shifted towards small cars. Similarly, the governments should be told that any plans for raising crash safety standards should be frozen if they want to put emission reduction on first priority. You can’t have your cake and eat it too.

The rest of the improvement will be responsible by manufacturers. They can employ more lightweight materials such as aluminum, magnesium and composites wherever cost effectively. They can cleverly design the chassis structure to lose weight without losing rigidity. They can set a weight target for each component and give incentives to component suppliers which can design components lighter than the targets. They can integrate different audio and infotainment systems into one unit. They can combine various microprocessors into a central brain. They can develop lightweight seats and fabrics… Every sector can trim weight.

In fact, under the pressure of emission reduction, the trend of weight increment is arriving the U-turn now. The latest BMW 3-Series, 5-Series and Mini are no heavier than the cars they replaced. Ditto the new Mercedes C-class. The new Audi TT is even lighter than the first generation thanks to the aluminum-steel hybrid chassis. However, a more important indicator is probably the next generation Mazda 2, which has been shown in Geneva motor show and will go on sale later this year. The Mazda 2 is slightly smaller than the old car (40mm shorter, 55mm lower and only 15mm wider) and it is 100kg lighter. Expect more cars will follow suit.

Nevertheless, a greater problem lies in the mix of our car population. Since the late 1990s, customer taste has been shifting towards heavier vehicles like sport utilities, multi-activity vehicles and crossovers. As a result, car makers develop, promote and sell more these vehicles and lead to a dramatic increase of greenhouse gas emission. In the United States, the increase actually canceled out the reduction achieved by the progress of green technology. Both consumers and car makers should be responsible for the problem.

Undoubtedly, we have to stop the trend towards heavier types of vehicles in order to reduce overall emission. This is exactly where legislation may help – for example, a tax system according to emission level will drive consumers away from sport utilities and crossovers etc. so that manufacturers can concentrate their resources in developing smaller cars and greener technologies. Rearranging the mix of our car population is probably the easiest and cheapest way to cut the overall emission drastically. If half of the sport utilities and light trucks in the USA are converted to cars, the average fleet emission could be reduced by more than 10 percent immediately !

One thing is very interesting: by making our cars smaller and lighter, they could be actually more fun to drive ! As I always said, more power does not equal to more fun. A Porsche 911 Turbo (307g/km) is not necessarily more pleasurable to drive than a Cayman S (254g/km), Lotus Elise S (196g/km) or Mazda MX-5 (183g/km). Lightweight cars are more agile and easier to place in tight roads. Their lack of sound deadening, NVH suppression and driver assistance usually bring more direct feel to the drivers. In the future, legislation against emission will push manufacturers to shift their high performance cars towards smaller ones. Lightweight roadsters and coupes will rise again. Super-powerful performance sedans like BMW’s M cars, Mercedes’ AMG and Audi’s S lines will suffer the hardest blow. At least their numbers will be limited to avoid lifting the average fleet emission level. The top super cars like Ferrari or Lamborghini, however, will not be influenced much, because they are already very limited in numbers. They can be exempted from legislation.

There is worry that fuel saving technologies could hurt driving fun. To certain extent, yes. A diesel engine is nowhere as eager to rev as a gasoline engine. A hybrid powertrain adds weight to the car. An electric power steering is not as feelsome as a hydraulic one. On the positive side, diesel engines provide superior bottom-end torque for instant acceleration. Diesel technology is also progressing much quicker than gasoline technology so that one day it might just match gasoline engines for subjective feel. Hybrid powertrain might bring extra weight to the car, but on the plus side we can place part of the weight, say, the battery pack and inverter, at more favourable position to balance the car. The flat torque curve of electric motor also helps the car to get off the line more quickly than internal combustion engines can do. As for electric power steering, there is no reason why it can’t be improved to provide real feel in the future. In short term, any dramatic changes in automotive technologies will inevitably cause some drawbacks, just like the series of new safety and smog control regulations worsened the cars in the mid-1970s. Anyway, sooner or later car makers will overcome the problems and make better use of the benefits brought in by the new technologies.

In the future, the key to survival is technology. Developing green technologies require substantial and long term investment. Only the biggest manufacturers can afford. Smaller companies will be eliminated if they fail to form alliances to share technologies and costs. Mitsubishi and Proton are in the risk. UK sports car specialists had better to pray for an exemption for low volume car makers, otherwise they will be the victims. Well prepared companies like Toyota and BMW will be the winners. The same goes for small car specialists like Fiat and Suzuki. GM, Ford and Chrysler will survive anyway, but they will be seriously hurt because they are still building very large cars and trucks today. Hyundai group could also face difficulties to persuade people buying its cars at higher prices. So far it has shown little commitment to green technologies. Porsche could be a big loser because it produces only performance cars while its production volume of 100,000-plus units is unlikely to get exemption. Luckily, it bought Volkswagen recently. Other players like PSA, Nissan-Renault, Honda and Mercedes will be able to survive through alliances or working with component suppliers.

Global warming is going to change the view of our motor industry, our cars and our driving habit. Like it or not, you have to prepare for its coming.

Mark Wan