18 Advantages and Disadvantages of Diesel Cars

Diesel engines are found in all vehicle classes. Although they are usually seen in the United States in semi-trucks and other large vehicles, there are passenger cars which use this engine too. Europe sees an even higher use of this technology, with about 50% of all new vehicles sold there using this fuel resource.

Kids of the 1980s and their parents might remember the days of leaded fuel and diesel creating heavy levels of smoke and exhaust that could be extremely bothersome. You could sometimes smell the fuel in the cab of the vehicle just by rolling the windows down. New technologies have helped to clean this issue up, virtually eliminating all of the complaints from the previous generation for diesel engines.

There have been fuel emissions violations from major manufacturers, such as Volkswagen, that may have soured some people to this technology. The fact remains that there are significant pros and cons of diesel cars to consider if you’re in the market for a new vehicle right now.

List of the Pros of Diesel Cars

1. Diesel cars have an excellent fuel economy.
Diesel engines are more fuel efficient than their counterparts. The fuel itself contains more energy than 100% unleaded or ethanol/gasoline blends. You can expect to see a 15% or greater gain when you purchase a vehicle equipped with this technology when compared to the “normal” vehicles sold today. That means you’ll receive up to 35% more fuel per mile/kilometer when driving as well. This advantage is possible because diesel engines have improved power, acceleration, and efficiency.

2. Diesel cars offer a longer range than comparable models using unleaded fuel.
If you want to own a vehicle with an extended driving range, then diesel cars are your best investment option. The Chevy Cruze diesel sedan, when you choose the six-speed manual transmission, gets up to 52 miles per gallon on the highway. That gives you a range of over 700 miles on a single fill-up. The Jaguar XF 20d goes even further, giving you a range of 731 miles. Although there are some hybrid vehicles that are catching up with this technology, diesel is still at the head of the class.

3. Diesel cars don’t have a spark plug or distributor to worry about for maintenance.
Diesel engines don’t require an ignition tune-up like other cars do. They also tend to last longer than engines that use a standard gasoline before requiring a significant repair. You will still need to have frequent filter and oil changes to keep your vehicle in a good operating condition. Some owners may need to address their urea injection systems to maintain performance. Most engines are designed in a way that the time and investment needed to keep them running are minimized for owners.

4. Diesel cars offer higher levels of durability.
Diesel engines offer a greater level of durability because their engine speeds are about 50% of what a gasoline counterpart endures each day. No engine will last forever, of course, but the higher compression ratios and high torque output requires robust engineering that leads to longer life. Diesel cars have an engine which operates at a lower RPM as well, which means there is less friction on the cylinder walls, piston rings, bearings, and other elements.

Gary Mueller provides evidence of this durability with his Ford F-350 Super Duty diesel pickup. He purchased the vehicle with a 7.3L Power Stroke engine. He reached 300,000 miles in no time at all, which was a time when his family and friends suggested he get a new truck. By 2011, Mueller topped 1 million miles on the original diesel engine. His story is featured on Mother Earth News.

5. Diesel cars offer drivers better torque during acceleration.
A Dodge Dakota pickup fitted with a 359 6-cylinder diesel recent made 1,300 lbs.-fit of torque during a run at the Bonneville Salt Flats at more than 220 miles per hour. The engine is turbocharged, but this record run is still evidence of the power that diesel cars have over gasoline vehicles. One gallon of diesel fuel contains about 147,000 BTUs of energy, while a similar amount of standard unleaded gasoline contains only 125,000 BTUs. Although that means less overall horsepower, you’ll have a lot of power in the low rev range when you choose this option instead.

6. Diesel cars have a lower cost of ownership compared to gasoline vehicles.
Although diesel owners might see an increase in charges for standard maintenance services on their vehicles, the lifetime cost of ownership is usually much less than a car operating with an internal combustion engine. The University of Michigan Transportation Research Institute discovered that in just three years of ownership, diesel owners save over $2,000 in maintenance and repair costs. When that figure goes out to 5 years, then owners can save up to $7,000.

7. Diesel cars can run on alternative fuels.
There are no significant modifications required for a diesel engine to begin operating on a renewable fuel resource. Biodiesel can be used by drivers safely without costly changes. Most manufacturers make their engines compatible with a biodiesel mix of up to 20% without creating an issue with the car’s warranty. Although some gas-powered vehicles use ethanol in the same way, most only operate on a 10% to 15% mix.

8. Diesel cars are excellent for towing.
You can own a small diesel vehicle and still have a workhorse when there is a need for towing. The pulling power of a four-cylinder engine operating on diesel fuel is comparable to a six-cylinder gasoline engine. Although the horsepower ratings are often lower, and the diesel vehicle will have a lower maximum speed, the power drivers have behind the wheel more than makes up for a potential speed disadvantage.

9. Diesel cars start well in cold weather.
If you owned the previous generation of diesel cars, then trying to get the engine started in the winter during a cold day was a challenge. You would need to use glow plugs to help generate enough heat, over 20 seconds of time (and sometimes more) to achieve the correct temperature for combustion. The modern diesel engine using a pre-heating system that will help the vehicle start almost immediately, even in extreme conditions, which makes it comparable to most gasoline engines today.

List of the Cons of Diesel Cars

1. Diesel cars are typically more expensive than their counterparts.
Because there are greater manufacturing needs involved in the construction of a diesel engine, you’ll pay a premium price when compared to a car which operates on standard gasoline. The average vehicle owner will pay about $2,500 more for a vehicle equipped with a diesel compared to one with a gasoline internal combustion engine.

That capital cost is much lower than other alternative fuel options in today’s vehicle market, however, as a hybrid typically costs $4,100 more than a standard gasoline option. If you choose an electric vehicle over one that runs on fuel, then you’ll pay a $13,000 premium. That’s why choosing diesel is often a good investment.

2. Diesel cars cost more when performing ongoing service and maintenance tasks.
Although diesel cars are cheaper when compared to gasoline vehicles from an overall perspective, there is a higher cost that drivers face when they do need to have work completed on their vehicle. There is also the requirement that all new vehicles equipped with a diesel engine must have a reservoir of urea. You’ll spend more on each service call, but most drivers have fewer needs to get to their mechanic. The costs balance out most of the time. If your vehicle is going in for repairs often, however, there will be a noticeable difference here with this disadvantage.

3. Diesel cars operate on a fuel resources which can sometimes be challenging to find.
Fuel stations do not always carry diesel fuel. According to information published by Green Fuel Reports, about 50% of all retail fuel sites carry this option. If you’re unfamiliar with a certain area because you’re traveling, then it can be challenging to find the fuel you need if your tank begins to run low. Most of this issue is still due to a throwback from the 1980s when this fuel was dirty and saying its name was treated like a four-letter word. Drivers no longer need to fill up with the semi-trucks, but there is still an attitude in the U.S. that it isn’t the best option to consider.

4. Diesel cars operate on fuel that is more expensive.
The average price for fuel in the United States for the second week of January 2018 was $2.54 per gallon. During that same week, the average cost of diesel was $2.94 per gallon. Most drivers will experience a higher cost per gallon when filling up a tank with diesel compared to using 85-octane unleaded fuel. If you have a 15-gallon tank to fill, that difference comes to about $6 per stop.

That’s when you compare only 85-octane fuel to diesel. Drivers have the option to choose 87-octane products, 89-octane gas, and a premium product in the 90s at most stations. When you choose a 90+-octane gasoline, the cost is almost exactly the same as it is for a standard diesel fuel.

5. Diesel cars focus on torque instead of horsepower.
If you’re looking for a vehicle which can give you a rapid acceleration profile, then a diesel car will not perform the same way as a gasoline internal combustion engine. Diesel fuel is more about strength instead of speed. This option is the one to choose when you have a fifth-wheel to tow, mountains to climb, or farm work to finish. It will still perform to your expectations, but it may not beat another driver off the line when the stoplight turns green.

6. Diesel cars are often louder than their counterparts.
When you listen to the sound output from a gasoline internal combustion engine, most of the operating noise comes through the exhaust. That’s why a muffler is placed on the system. It reduces a majority of the noise pollution the vehicle generates. Diesel cars are a different story. The majority of the noises that diesel technologies produce come straight from the engine itself. Even when insulation is provided to deaden this noise, there is certainly more clatter to consider with this option.

7. Diesel cars offer less efficiency with city driving.
If you own a Volkswagen Jetta TDI, then you would receive 42 miles per gallon when on the highway with your vehicle. Driving in the city, with its starts and stops, would give you just 30 miles per gallon. There is a steep drop-off in fuel efficiency when comparing diesels to gasoline and hybrid vehicles that must be considered before purchase.

These diesel car pros and cons show us that it is time for the United States to give this technology a closer look. The numerous benefits in fuel efficiency and engine durability make it a potentially wise investment option, especially when one considers the potential savings. If you plan to own the vehicle for 5+ years, then the increased cost when purchasing the vehicle are usually made back by then.

About the Author
Brandon Miller has a B.A. from the University of Texas at Austin. He is a seasoned writer who has written over one hundred articles, which have been read by over 500,000 people. If you have any comments or concerns about this blog post, then please contact the Green Garage team here.