Excerpt from Chapter 1 of Save Gas, Save the Planet: John Addison’s book about hybrid and electric cars, pathways to low carbon driving, and the future of sustainable transportation. © 2009 John Addison. All rights reserved.
Diesel
Over half of all car sales in Europe use diesel engines not gasoline. Diesel fuel contains more energy per gallon than does gasoline. Diesel engines are far more efficient than gasoline. I have enjoyed driving the new diesels from Volkswagen, Mercedes and BMW. Performance was excellent, and the driving experience was smooth and quiet.
The exhaust was invisible and without odor. The new cars perform far better than old diesel trucks and buses that can be loud and have annoying exhaust. If you plan to buy a German car, make turbodiesel your first choice. The car will probably use 25 percent to 40 percent less fuel than its gasoline counterpart.
Turbocharging compresses and delivers more air to engine cylinders, resulting in the same amount of diesel fuel delivering better mileage and performance. It took awhile for these new turbodiesels to get approval to be sold in the United States because of new federal and state emission standards and because of requirements for ultra-low sulfur diesel fuel. All new offerings are likely to be turbodiesel, so I will simply refer to these vehicles as diesel.
Should your next car be a hybrid or a diesel? The answer depends on the type of driving you do and if you want a car, truck, SUV, or minivan. The best hybrids deliver better mileage in stop-and-go city driving than do diesels. Diesels can get over 40 miles per gallon on freeways, while hybrids often have better fuel economy in city driving than on the highway.
You might also prefer a diesel engine if you are enthusiastic about biodiesel, which blends fuel from plants or waste, instead of only being sourced from petroleum. In the chapter about biofuels, you will see that some blends of biofuels help the environment while others hurt. Some types of biodiesel helps performance, others can void vehicle warranties or damage engines. The new diesels, with their high-pressure injection, demand a much higher quality fuel than the diesels of yesterday. Most automakers can void your warranty if you use over five percent biodiesel in the new diesel cars, trucks, and SUVs.
Why not have the best of both with a hybrid diesel? This approach is slowly being adopted. Thousands of buses and trucks are hybrid diesel. Volkswagen and Mercedes plan to bring hybrid diesels to the United States that will deliver over 40 miles per gallon. GM plans to bring a plug-in hybrid diesel to Europe that will deliver over 100 miles per gallon.
Millions of trucks deliver our goods, run farms, help keep our cities running, and bring people to fix our homes. Diesel has long been the standard in big heavy-trucks. Diesel engines are more efficient than gasoline and the engines last longer. Diesel fuel packs more energy per gallon than gasoline. Diesel is increasingly being offered so that light trucks can deliver more miles per gallon.
