With the advent of new technology, diesel engines are now available in all 50 states from numerous manufacturers. Diesel passenger cars and SUVs are offered by Audi, BMW, Mercedes-Benz and Volkswagen, while diesel pickup trucks are available from Chevrolet/GMC, Ford and Ram. More brands are offering diesel power every day.
Diesel engines are generally more expensive to manufacture than conventional gasoline engines because of the extra measure of durability required to withstand the stress of high-compression diesel combustion, technology such as turbochargers that improve performance and additional exhaust treatment needed to ensure clean air emissions. As a result, the purchase price of a diesel vehicle is generally higher than for its gasoline-powered counterpart.
In the past, diesel engines were thought to be noisy, smelly things suited only for industrial applications, but advances in technology have minimized these drawbacks. Much of the appeal of diesels comes from their fuel economy, which is typically better than that of their gasoline-powered equivalents. Sheer power can also be impressive, because lots of torque is available at low rpm, which makes diesel power preferred for towing. In general, diesels combine excellent low-speed tractability with fuel-efficient cruising.
Just as with gasoline-powered cars and SUVs, diesel-powered vehicles are fully equipped with modern safety features like antilock brakes, front-seat side airbags, full-length side curtain airbags and stability control. Convenience features like rearview cameras and parking sensors are becoming increasingly available on non-luxury cars, while premium brands are utilizing high-tech electronics to warn inattentive drivers of blind-spot intrusion and impending collisions. Shoppers should be aware of crash test scores, but it should be noted that the National Highway Traffic Safety Administration has adopted more strenuous testing procedures, so the ratings produced by some models in the past might not be directly comparable to new vehicles.
Interior passenger space depends on the model you select, but you'll find diesel-powered models in a surprising number of market segments across the board. Those who need an extra row of seats will find SUV models attractive, especially since bigger, heavier vehicles are well suited to a diesel engine, which combines plenty of low-rpm thrust with good fuel economy and cruising speed. Heavy-duty pickups can seat anywhere from three to six people, depending on whether you choose a regular-, extended- or crew-cab model.
While diesels used to be considered as industrial-strength transportation best suited to crude manual transmissions, a wide range of transmission choices now make the diesel engine a friendlier device with which to live on a daily basis. Automatic transmissions for diesels now have a greater number of speeds to keep the engine operating at peak power and efficiency, while automated manual transmissions foster improved fuel efficiency without losing the convenience of an automatic clutch.
The diesel combines the promise of low operating costs thanks to excellent fuel economy with a measure of added durability thanks to heavy-duty construction. The diesel delivers on both counts, but hidden costs can compromise the overall economics. First, the excellent mpg of a diesel can be partially offset by the higher price of diesel fuel. Second, the greater durability of diesel hardware can be offset by the costs of maintaining the emissions hardware, which might include a liquid after-treatment of the exhaust to reduce particulate emissions. Finally, minimal running costs can be offset by a greater purchase price for the engine itself. In the end, the appeal of the diesel equation depends on use, and if you're after either extreme cruising range or pronounced towing capacity, the diesel could be for you.