Another motoring milestone: a diesel production sports car. Appropriate, too, that Audi -- winner of the past two Le Mans with diesel-powered R10s -- should be at the vanguard, and apposite that power should come from a new diesel engine of uncanny smoothness, frugality, and performance. We're talking a blend of 140-mph 0-to-60 acceleration in about seven seconds and 50-mpg average. Welcome to the sports car of the future.
There are no firm plans to sell the TDi in the U.S., but such is the momentum for saving oil and so strong is the rising interest in diesel cars Stateside that nobody's ruling it out in the future. The 2.0-liter four-cylinder diesel is borrowed from the latest Audi A4, power-boosted from 143 horses to 170, mostly due to a meatier turbocharger. As with all good diesels, it pulls like a train from low revs but sounds like a truck at big revs: The redline is a high (for a diesel) 5000, but the TDi gets coarse over 4000. There's just no point hanging onto the revs much past 3500 (torque peaks at 2500). This is always the downside of diesel: Forget about the delicious throttle control that comes from high-revving tuneful gasoline motors or zestful engines that yearn to rev.
Yet the TT TDi is a true sports car: It goes hard, handles well, steers nicely, and has most of the qualities of the TTS, but at a lower price and with far better fuel economy. If 50-mpg sports cars of the future are all like this, driving is still going to be fun.