Gas Engines Vs. Diesel Enginesby Tim Plaehn
Buyers of several types of powered vehicles, including boats, cars, pickup trucks and medium-duty trucks, often have to choose between gas and diesel engines. Each type of engine has pros and cons, and the best choice depends on how you plan to use the vehicle.
The cost comparison between gas and diesel engines depends on whether you plan to be a long-term or short-term owner. The initial cost and the prices for replacement parts and repair are significantly higher for diesel engines. However, the heavy-duty design of most diesel engines will allow them to run without a major problem for two to three times longer than typical gas engines. Vehicles with diesel engines also tend to have higher trade-in or resale values, which may allow you to recoup some of the initial cost when you sell the vehicle.
For the same vehicle model, the top gas engine option will usually have a higher horsepower rating and the diesel option will provide higher torque. Gas engines are quicker to rev up, and the higher horsepower at higher revolutions per minute (rpm) allows gas-powered vehicles to accelerate faster. Diesel engines develop their higher torque at lower rpm. Torque provides steady acceleration and power to pull or carry heavy loads.
A big advantage for diesel engines is fuel economy. Their direct injection and compression ignition, along with the higher energy density of diesel fuel, produce better fuel mileage in diesel-powered vehicles. For high-mileage applications, the fuel mileage advantage of diesel can provide significant cost savings over gas. Diesels can also burn bio-diesel fuel without modification.
Having fewer locations where you can buy diesel fuel is considered a significant drawback to diesel ownership. Parts and repair facilities for diesel engines are also less widespread than services for gas-powered vehicles. Diesel engines also may produce a level of noise and vibration higher than the typical gas engine. Diesel fuel is messier than gas, and most diesel owners carry a pair of gloves to use when fueling.
Diesel engines have distinct advantages over gas if the vehicle is used to carry or pull heavy loads. Diesel engines produced and sold after 2007 must meet stringent emission requirements, resulting in exhaust emissions comparable with new gas engines.
- photo_camera Image by Flickr.com, courtesy of Graham Richardson