Tractors have a lot to answer for.
While they've furthered agriculture to the benefit of the greater good, their use of torquey, grumbling diesel engines has subsequently afflicted every road-going diesel with the description "it sounds like a tractor".
Except that unless you've been hiding under a rock for the last two decades, that's no longer the case. Diesels these days are damn good. But can they ever be truly desirable - even sexy?
It's a question we've pondered after driving two of the more desirable vehicles on the road, powered by diesel engines. One was the Jaguar XF 2.2D, which has fewer cylinders and runs on the "wrong" fuel compared to traditional Jaguars, and the other was the 2012 Range Rover Evoque, a design icon already and powered by the same 2.2-liter turbodiesel powerplant. We drove both in the U.K, but neither diesel is earmarked for the U.S.
Both are exceedingly desirable cars, with style and luxury aplenty. Neither feels under-endowed in the engine department, and neither is anything less than refined.
Neither is quite as smooth as its gasoline equivalent, but both make up for it with torque and near-silence at cruising speeds - and in luxury vehicles, torque and silence are both desirable qualities. It's only a pity that neither is on sale in the U.S.
Other carmakers that do sell diesels in the U.S. have done much to improve the fuel's image. BMW and Mercedes-Benz, for example, both sell fairly rapid sedans that drink from the diesel pump, and both have enough performance that you can choose them on merit over their gasoline equivalents.
Then, you have Volkswagen, whose TDI engine is almost the default choice for its Jetta - the model would certainly be less of a success were it not for its 42 MPG highway rating, and the potential for even more.
Thriftiness isn't considered a sexy or desirable quality, but coupled with decent performance and low noise there's certainly less reason to pick the gasoline version.
And that, we think, is what it's about.
While diesels sell on the back of economy, performance and refinement are key to making them the pick of a range. People don't really care what powers their car if the fuel in question makes it a better vehicle. They might be sexy despite being diesels, but you'd no longer have to apologize for your choice of fuel.
Provide those characteristics in an already-desirable vehicle like a Jaguar, Range Rover, BMW, Mercedes or similar, and they have a pretty strong case.
And best of all, the word "tractor" won't even cross your mind...