Beschreibung

Those familiar with VW/Audi’s naming conventions know TDI is the acronym for Turbocharged Direct Injection, the German automaker’s revolutionary diesel power plant that made its debut back in 1990 in the form of an inline five-cylinder powering the Audi 100 Wagon. So the next question is, “An R8 with a diesel?!” In short, yes.

Sources say Audi has a diesel-powered R8 in the works, and we’d like to think they’re right. As far as cutting-edge diesel technology goes, Audi’s one of the best in the biz. Its latest demonstration of spark-plugless prowess came in the form of the R10 TDI race car, winning its very first race at the 12 Hours of Sebring as well as the infamous 24 Hours of Le Mans and the Petit Le Mans. So who better to make a diesel exotic?

The bigger question—especially for us in the U.S.—is why would Audi want to put a diesel in a car that already is so good in its present form? We know, clean diesels have proven they are for more than big pickups and school buses. Europeans swear by them. They would give up anything to pay a measly $3.45 a gallon like we do, while our low gas prices over the years prevented diesels’ torquey richness from being brought to the U.S.

We realize European buyers with $110,000-plus for an R8 TDI are not counting the change in their piggy banks for gas money. So, we suspect that it’s an image thing, or that they are addicted to the torque.

This brings us to the next question: Which engine would Audi use in an R8 TDI? While there are a mess of TDI powerplants to choose from, rumors and our educated guesswork narrows it down to three possible choices. Consider them the good, the bad, and the ridiculously impractical.

All three powerplants can be found in the Audi Q7 SUV. First, the good: the 4.2 TDI V-8 which makes a solid 326 horsepower backed by 561 pound-feet of torque. Next, the bad: the 3.0 TDI V-6 that puts down a very sub-exotic 233 horsepower, although it makes its fair share of torque at 369 pound-feet. Last, and certainly not least as far as sheer power goes, is the ridiculously impractical 5.9 TDI V-12 influenced by our aforementioned friend, the R10 race car. This beast lays out a mind-numbing 493 horsepower and 738 pound-feet of torque.

So naturally our choice would be the 5.9 TDI right? Unfortunately, just as reality strikes us each week when our paychecks arrive, so does it remind us of practicality, and the 5.9 TDI ain’t that. It’s far too heavy for a sports application such as the R8, not to mention with that kind of power Audi may be overstepping its bounds with subsidiary Lamborghini. What a shame. We really wanted to see a car that would literally break your neck under acceleration.

On the flip-side, the 3.0 TDI V-6 seems a little anemic for an exotic—233 horsepower would only cut it in something as light as the Ariel Atom, but at 3500 pounds, the R8 isn’t what we’d call ‘slim and trim’. Torque numbers aside, the 3.0 TDI falls short. So, two down now, one to go.

That leaves the 4.2 TDI V-8 as the obvious choice. Making only 22 percent less power than the current gasoline powered 4.2-liter found in the R8, it would produce a whopping 77 percent more torque! That’s 77 percent more force throwing you back into the seat when you hit the throttle, and maybe even 77 percent more fun. In the gasoline R8, the 317 lb-ft of peak torque hit high at 4500 rpm. In contrast, a 4.2 TDI V-8 R8 would make 561 lb-ft starting at 1800 rpm all the way to 2500 rpm. Now that’s what we call low-end grunt.

The 4.2 TDI propels the Audi Q7 from 0-to-62 mph in a claimed 6.4 seconds—and that’s an SUV. Factor in better gearing, less weight, and more grip and you start to get a feel for what the R8 4.2 TDI would be capable of. In addition, the diesel engine weighs less than 600 pounds, which isn’t too bad for a car on a diet.

Oh, and we can’t forget about the gas mileage. According to our estimates using the Q7 as our guidepost, the EPA fu