New diesels: they're not like the old diesels. Find out why.

Dear Car Talk

Dear Car Talk | Sep 01, 2007

Dear Tom and Ray:

I commute 130 miles round trip and am thinking about buying a new diesel Volkswagen. I'm worried about maintenance costs. I read that diesels make up less than 1 percent of the U.S. market, so will it be hard to find diesel mechanics and diesel fuel at a reasonable price? Will it be more trouble than a gasoline engine? -- Terry

TOM: Diesel passenger cars aren't really mainstream yet, but I don't think those concerns should hold you back these days, Terry. I think people, including us, are warming up to the idea of diesels.

RAY: For years we were vehemently opposed to them because they were noisy, smelly, smoky, shaky and slow. But a lot of that's changed.

TOM: The biggest change has been that federal law now requires diesel fuel sold in the U.S. to be very low in sulfur. That, in turn, is allowing carmakers to make cleaner diesel engines that meet the same emissions standards as gasoline engines. That's a HUGE change for the better.

RAY: So, as these new diesels hit the roads over the next few years, diesels will no longer be identifiable by that disgusting cloud of gray soot that envelops them at every stoplight.

TOM: Plus, better manufacturing and insulation have also made them quieter and smoother. And improved fuel-delivery technology has made them quicker. So a new, clean diesel is a worthwhile consideration nowadays.

TOM: In terms of the costs, diesel fuel is currently more expensive than gasoline, but not by a lot. But since diesel fuel has more BTUs (more energy) per gallon than gasoline, you can expect 25 percent to 30 percent better mileage. Of course, you'll have to look around to make sure there are gas stations convenient to you that sell diesel. But on a per-mile basis, diesel fuel should cost you less.

RAY: Maintenance is probably a wash. While diesels don't need tuneups, because they don't have things like spark plugs or spark-plug wires, they do require more frequent oil changes. Or, more expensive synthetic oil. So let's call that even.

TOM: And in terms of more serious repairs, you might come out ahead with a diesel there, too. Well-manufactured diesel engines are known for their durability. And while everybody seems to be jumping into the diesel game all of a sudden, lots of carmakers, including VW, have been making and selling diesels in Europe for years.

RAY: We haven't driven the newest VWs yet, but we stood in front of a new diesel Jetta recently, and we were impressed by how quiet it was. Even AFTER they started the engine. And we weren't even asphyxiated by the exhaust.

TOM: While diesels make up only a small percentage of the passenger-car market right now, their share is probably going to grow over the next decade as gasoline stays expensive and mileage becomes more important to car buyers. So I'd say, go for it, Terry. And if we're wrong, we'll send you a free pair of combination Car Talk earplugs/nose plugs.

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