It's a common complaint: Never mind hybrids, why can't we buy the high-mileage diesel small cars used by drivers all over Europe?
The answer: Most of them weren't designed to meet US safety and emissions standards. But now, Audi plans to offer a diesel version of its A3 hatchback, and Mini is considering bringing its Cooper D diesel to the US.
The US has the toughest emissions laws in the world, and the latest round--known as Tier 2, Bin 5--knocked every diesel off the market for almost two years. Diesel engines are already more expensive to build than gasoline burners, because they need to be tougher to withstand the much higher compression ratios used to compress and ignite the diesel-air mixture without a spark plug.
Adding complex emissions gear, from special-purpose catalytic converters to diesel particulate filters, ratchets up the cost substantially. So most diesels planned for the US market come at the higher end, notably from diesel pioneer Mercedes-Benz (which has been making them since 1938) and more recently BMW, whose 335d and X5 diesel were just granted tax credits by the IRS.
The one modestly-priced exception is the 2009 Volkswagen Jetta TDI (and its Sportwagen variant). But diesels are offered in every European car class, and they're as common in tiny hatchbacks as they are in big Benzes. Most European makers now have a super-economy model with special branding in every line, all of them using high-output turbocharged small diesels. One great example is the Ford Fiesta EcoNetic, which returns a solid 61 miles per gallon. But again, the EcoNetic engine doesn't have the emissions systems to be legal in the US.
So what are the chances for small diesel cars in the US? Audi is a premium brand here, and its A3 hatchback easily passes the $30,000 mark if fitted with a big engine and Quattro all-wheel-drive. So Audi buyers might not look askance at a TDI version at those levels, provided it had the performance to match its image.
But the Mini Cooper D could be a tougher sell. Minis start in the low 20s, before their buyers personalize them with a plethora of options, and they're known for go-kart handling and peppy disposition. Would a diesel Cooper be too much of a stretch? Only time (and perhaps some quiet market surveys from Mini) will tell.
[Cooper D photo from Flickr user TheMullett.]