Diesel Engines: Pros & ConsLast Updated June 13, 2023 | Alison Smith
Heavy-duty trucks are known for their diesel engines, some of the most common being the Cummins, Powerstroke, and Duramax. Not only do diesel engines provide more power, which is especially important when you need to haul or tow heavy items, but they also offer great fuel efficiency. Even light-duty trucks now offer diesel engine options, with Ford, Chevy, and Ram all having hopped on the bandwagon. Diesel engines still remain more popular overseas than they do here in America, with 45% of buyers in Western Europe opting for diesel-powered vehicles, according to the European Automobile Manufacturers Association. That’s a pretty high percentage, considering diesel-powered vehicles make up less than 5% of the market in America. Although trucks are traditionally seen as diesel powerhouses, many automakers are beginning to offer diesel-powered cars for better fuel efficiency and durability.
Pros & Cons of Diesel
As with most things, there’s no cut-and-dried answer when it comes to the diesel vs gas debate. People are usually going to prefer one or the other, but there are many advantages of diesel engines to consider when shopping around for a vehicle.
Pros: Advantages of Diesel Engines
- Highly efficient: Diesel engines utilize a compression-ignition system that is much more efficient than gasoline engines. Rather than using spark plugs, diesel engines require more compression in order to heat the air. Since the compression is greater, the temperature of a diesel engine is hotter than a gas-operated motor. Because of this system, diesel engines produce more energy and require less fuel at the same time. This greatly increases gas mileage and the length you can travel before having to fill up again.
- Durable: Because they are engineered to withstand higher temperatures, diesel engines tend to last longer than gas engines, assuming you keep up with all necessary maintenance.
- Greater torque: As diesel engines emit more energy in comparison to gasoline, they produce greater amounts of torque. If you plan on towing a trailer or hauling heavy loads on a regular basis, then a diesel engine may be a good option for you since it’s going to give you that extra power.
- Good resale value: Since diesel engines are extremely durable, they have a pretty good resale value as they can last a long time.
Cons: Disadvantages of Diesel Engines
- More expensive to purchase: Diesel-powered vehicles are typically more expensive than their gas-operated counterparts. Opting for a diesel vs gas engine can cost you up to a few thousand dollars.
- Fuel is pricey: Even though you save money by not filling up your tank as often, diesel, in general, is going to cost more than gasoline. Depending on how often you drive your vehicle or if you use it as a daily driver, you’d have to weigh whether the efficiency is worth the additional fuel price.
- Higher cost to fix: Diesel engines may be durable, but if you don’t keep up with the maintenance, they can cost more to fix than a gasoline motor.
- Less accessible: Finding a diesel-powered vehicle may be a difficult task as there aren’t as many of them. Diesel fuel can also be harder to find as not every gas station will carry diesel.
Newer diesel vehicles are mandated by EPA guidelines and are required to abide by certain fuel standards. While diesel used to be smelly, dirty, and pollute the environment, EPA regulations have made diesel fuel cleaner than ever. Ultra-low sulfur diesel, or ULSD, began replacing traditional diesel fuel in the U.S. starting in 2006. Now, ULSD fuel is required to comply with on-road and non-road diesel fuel standards. Previous diesel fuel contained as much as 5,000 ppm of sulfur. In comparison to ULSD fuel, the sulfur content is significantly less at 15 ppm.
Used in conjunction with advanced exhaust emission control systems, ULSD fuel can reduce nitrogen compound emissions by up to 50% and vehicle particulate emissions by up to 90%. Although ULSD fuel is much more environmentally friendly than high-sulfur diesel fuel, air pollution is still an issue for older diesel engines.
Sources:Ultra-Low Sulfur Diesel, U.S. Department of Energy | Weekly Retail Gasoline and Diesel Prices, U.S. Energy Information Administration | Diesel Fuel Standards, United States Environmental Protection Agency | Diesel Fuel Explained, U.S. Energy Information Administration | How Rudolf Diesel's Engine Changed the World, BBC | Image Credit: Consumer Reports, media.ford.com