The Case for and Against Buying a Diesel Car

Like soccer, diesel cars are a worldwide phenomenon that Americans just don't get.

In Europe, more than 50% of new cars sold have diesel engines, according to the European Automobile Manufacturers Association. Meanwhile, the U.S. auto market share for diesels hovers around 3%, says Jessica Caldwell, a senior analyst at the website

But there are signs diesel cars are becoming more mainstream, she says.

Improving technology has largely eliminated the noise and black smoke that used to follow diesels.

These days, diesels are designed to run on a new, low-sulfur version of diesel fuel, sometimes called "clean diesel," which produces less pollution and cuts back on that sooty smell reminiscent of the '80s.

Today, higher gas prices have made Americans more open to alternative fuels. But the push for diesel also is being driven by the automakers, says Hague Stoddard, an industry analyst for the website Wards Auto. To meet new fuel-efficiency standards, they'll need to boost the average mileage of their U.S. fleets from 27.5 miles per gallon to 35.5 mpg by 2016.

To do that, automakers that already build diesels overseas are bringing them to the U.S. German brands have the most diesel options available, but U.S. brands are making diesel moves, too, with GM and Chrysler joining the mix, Stoddard says.

But is a diesel car right for you? Here are the pros and cons.

High gas prices heading into summer aren't unusual, but with the price per gallon of regular unleaded hovering near $4, car buyers are likely going to be looking for a way to reduce fuel consumption, says Paul Taylor, chief economist at the National Auto Dealers Association in McLean, Va.

"If Americans were to become convinced that gas prices were permanently higher, that certainly would increase the interest in diesels," he says. "They attain stronger mileage, and they are certainly going to be attractive as gas prices move up."

A typical diesel engine gets around 30% better fuel economy than its gas counterpart. That's a big advantage, Taylor says.

If you frequently drive long distances or just don't like taking the time to fuel up, the fact that a tank of diesel will get you much farther than a tank of gas also can be a plus, he says.

While Caldwell expects most car buyers concerned with fuel economy to opt for hybrids or fuel-efficient compacts, those reluctant to downsize to a smaller car may find themselves attracted to diesel cars, she says.

"I think most people are going to be going to a diesel from a fuel-savings standpoint because there is no real difference in the body styles or designations of a diesel versus a nondiesel," Caldwell says.

Unless you're a drive-it-till-the-wheels-fall-off type, resale value is an important factor in the overall cost of owning a car. At the end of your time with a car, if you can resell it for more, you'll have lost less to depreciation. In effect, you will have paid less to own it.

Diesels have a distinct advantage when it comes to resale, says Taylor. For example, a low-mileage 2009 Volkswagen Jetta TDI diesel will fetch more than $3,000 more on average than a 5-cylinder, gas-powered Jetta GLI in similar condition, according to NADA data.

That's because diesel engines have a reputation for having better durability than gasoline engines.

"They are typically long-lived engines, and because they are more expensive new -- typically at least $5,000 more than any equivalent gasoline-powered engine -- they are sought-after in the used market," Taylor says.

Caldwell agrees. "There's a consumer notion out there that diesel engines last a long time," she says. "In fact, I own a 1980 Mercedes-Benz diesel. It is 32 years old and it is built extremely solid, and I do not think it is ever going to die."

The greater power of diesel compared to gasoline gives diesel cars an advantage over gas when it comes to torque, or the twisting power generated by an engine.

But even if you don't know what torque is, you probably know that feeling of power that comes from planting your foot on the accelerator of a car with a big engine, especially when you're passing on the highway or towing a heavy load.

Diesel gives you that same feeling with a smaller engine that gets better mileage, Caldwell says.

"The driving dynamic is a bit different with having generally more torque on a diesel than a nondiesel vehicle," Caldwell says. "There is always that quirky feeling when you drive a diesel and that is from the acceleration. I think people like that feeling."

One thing potential diesel car shoppers will notice immediately is the price difference between comparable gas and diesel versions of the same car.

Caldwell says selecting the diesel option on a new car can run from $2,000 or more over the gas-powered equivalent, depending on the brand and price range of the model.

Especially with more high-mileage options available among gasoline-powered cars, buyers may decide the fuel economy bump isn't enough to justify the price, Caldwell says.

"If you look at gas-powered subcompact or compact cars, their fuel economy is a lot better than what it used to be," she says. "That's something that every automaker is trying to improve, and it is very competitive."

The price of diesel fuel compared to gas has fluctuated historically, but in the past few decades, diesel has generally been more expensive than regular unleaded.

"There is an additional cost per gallon of diesel that makes it cost about as much as premium fuel, so that offsets some of the savings," Taylor says.

While it's not nearly as hard to find as other alternative fuels such as E85 or natural gas, diesel fuel can be hard to find in some areas, forcing drivers to hunt for it, Caldwell says.

"You do have to plan a little bit ahead of time. Not every gas station has it, so I think that is a potential negative," she says.

Another big downside to diesel cars is the limited selection of models available in the U.S., Caldwell says.

"Volkswagen makes up nearly a quarter of all diesel sales in the United States," Caldwell says.

While Volkswagen diesels are popular for good reason, having one automaker that dominates the diesel market illustrates how few choices there are in the marketplace.

The lack of interest in bringing diesel options to the U.S. has its roots in the disastrous diesel models introduced quickly in reaction to fuel shortages in the late 1970s, says Stoddard.

"The diesel engines that the U.S. and European manufacturers were selling back in the '70s and '80s were not well-designed. Their emissions let off a bad smell for one thing. They were noisy, and oftentimes they had a hard time starting in cold weather. That just turned people off for a long time," Stoddard says. By 1988, it had driven diesel sales down to just 0.2% of total U.S. car sales, according to the Department of Energy.

Caldwell says if diesel sales among passenger cars grow substantially, that shortage of available options should improve, as many automakers have diesel engines available elsewhere that could be brought to the U.S.