Audi RS5 TDI Concept

Audi adropped its biggest hint yet that a high performance ‘driver’s diesel’ aimed squarely at the likes of evo  readers will figure in its model line-up before too long. It’s called the RS5 TDI Concept and, among other things, it showcases the ‘e-boost’ electric turbo assist technology slated for the next-generation 3-litre V6 TDI biturbo engine. Said motor debuts in the facelifted A6 and A7 from the summer in 215 or 268bhp tune. However, the big news is that a 380bhp oil-burning ‘RS5’
thus equipped, and wielding 750Nm of torque from just 1250rpm, has step-off acceleration that almost beggars belief, a soundtrack that wouldn’t disgrace a bassy, large-capacity petrol V8, and enough raw pace to keep an RS6 Avant honest.

Described as a work in progress by Audi’s head of TDI development, Ulrich Weiss, it nevertheless clearly signposts Audi’s chosen future direction. Weiss remains tight-lipped for the moment about when we can expect to see this truly hot diesel Audi in the showrooms and whether it will wear an ‘RS’ badge or, less controversially, join the ‘S’ ranks. Officially, the go-ahead for such a car and its nomenclature hinges on customer reaction to the concept.

The ‘e-booster’ is a small electrically driven blower plumbed in between the intercooler and the induction system that gets the smaller of the V6’s twin turbos spinning rapidly before the hot exhaust gases can do the job effectively, giving more immediate throttle response away from rest and what Weiss calls a ‘pressure kick’ that eliminates off-boost lethargy when you get back into the throttle at the exit of a bend. The system operates up to 3000rpm, at which point it’s no longer needed and is bypassed entirely.

The handling circuit at Audi’s new Driving Experience Centre near Munich is just 2.1 miles long and, it has to be said, peppered with enough slow turns to hand an advantage to a car endowed with serious amounts of low-end punch and the traction to deploy it. The RS5 TDI Concept is that car and, presumably to ram the point home, a 552bhp RS6 Avant piloted by one of the driver training school’s pro drivers is waiting at the start line for the diesel to chase.

Diesels don’t sound good? Think again. Artificially  hyped  it  may  be,  but  this  one  has a warm, expansive, low-octave burble that swamps the low-rev sonic repertoire of the RS6 and builds to a satisfying, if somewhat muted, bellow at maximum effort. This, admittedly, is reached at a modest 4200rpm and there’s little point in venturing beyond that. But if you simply leave it in Drive and don’t touch the paddles, the automatic transmission’s brain knows this and does have eight rapid-fire ratios with which to sling the engine revs back into the heart of another mighty, torque-rich heave.

It isn’t quite seamless but it doesn’t seem to matter. There’s no straight long enough for the RS6 to pull away more than a car’s length and, with each successive lap, it becomes increasingly apparent that the lighter and torquier TDI has the fast estate’s number, more than clawing back any lost ground under braking and exiting the tighter turns.

Audi claims a 0-100kmph time of ‘around four seconds’, just a nominal tenth shy of that claimed for the RS6. It’s vindicated by a drag race along the main straight. The TDI’s initial push is simply brutal and, amazingly, it leaves the RS6 for dead off the line. The speedo’s showing a little over 113kmph before the big estate overtakes, and it doesn’t exactly waltz past. I’d love to know what the 0-48kmph time is.

At the very least, Audi has demonstrated that ‘RS’ and diesel power aren’t incompatible and the e-booster really works. The upshot is a car I’d have happily jumped in and taken the .

Engine V6, 2967cc, biturbo diesel
Power 380bhp @ 4200rpm
Torque 750Nm @ 1250-2000rpm
Performance 4.0sec (claimed 0-100kmph), 280kmph (claimed)
Weight n/a
Basic price n/a