Should you still consider a diesel car or SUV?

The 2018 Chevrolet Equinox—introduced to auto writers at an event in New York this week—will feature an optional four-cylinder 1.6-liter, 137 horsepower diesel engine.

General Motors

General Motors (GM) thinks you still might want to buy a diesel car or SUV.

Diesel sales, especially among sedans, have  slumped since 2015 after it was revealed that Volkswagen's popular TDI diesel models had passed the U.S, air pollution emissions test only by cheating. Volkswagen and its subsidiary Audi as well as Mercedes-Benz did not sell any 2017 sedans with diesel engines.  

Now General Motors is offering a diesel option in the fastest-growing U.S, automotive segment: compact SUVs. The 2018 Chevrolet Equinox—introduced to New York auto writers at an event this week—will feature an optional four-cylinder 1.6-liter, 137 horsepower diesel engine. Its corporate sibling GMC Terrain will also offer the diesel option.

The headline number with this engine is 39, the EPA rating for fuel mileage in highway driving. (The city number is 28 miles per gallon). Dan Nicholson, GM vice president for global propulsion systems, noted that the 39 mpg highway rating topped competitors Nissan Rogue (35 mpg highway)  and Toyota RAV4 (30 mpg) in their hybrid gas-electric versions.

"Diesel has definite benefits for customers who drive a lot of highway miles," said Nicholson.

Some independent analysts believe shoppers will shy away from the extra initial cost of diesel versions. "Diesel engines are usually more expensive to build than gasoline engines and thus are priced at a premium," said Jack Nerad, executive editorial director of Kelley Blue Book. Indeed the Equinox diesel is priced at $31,435, or $2,195 more than a comparable gasoline-powered version. "Diesels do offer higher fuel economy but in this era of low fuel costs that isn't a big advantage," Nerad continued.

Although the diesel in the Equinox—and in the Chevrolet Cruze small sedan—is new this year, Nicholson said the company had been encouraged by sales of a different diesel engine offered in 2017 models of its compact pickups Chevrolet Colorado and GMC Canyon. And V-8 diesel engines have remained popular in heavy-duty pickups like the Chevrolet Silverado 2500HD.

So with the Volkswagen episode in the past and current diesel offerings in honest compliance with EPA testing, should you consider a diesel if you are shopping for a new car? If you fit one of these categories below, you should at least do the research and compare the economics of diesel versions versus gasoline engines.

You have a long commute mostly at highway speeds. Not only do diesels put up good fuel mileage on the highway, you don't have to stop and refill the tank as often. GM says the new Equinox diesel has a range of 577 miles to the next refill starting with a full tank.

You need to tow a boat, trailer or camper. The strong torque of diesel at low speeds makes it ideal for towing. If you have heavy towing to do, consider a large pickup like the Chevrolet Silverado 1500 or its competitor the Ford F-150—both of which will have diesel options soon.

You think quick acceleration makes a car fun to drive. That same strong torque means plenty of zip when you hit the accelerator in a diesel vehicle. In a brief test drive, the new Equinox diesel lived up to that image. 

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    Jerry Edgerton, author of Car Shopping Made Easy, has been covering the car beat since Detroit companies dominated the U.S. market. The former car columnist for Money magazine and Washington correspondent for Business Week, Edgerton specializes in finding the best deals on wheels and offering advice on making your car last.