Audi RS5

 

What‘s it?
 A late-stage prototype Audi RS5, fitted with a really potent ‘e-boost’ version from the next-generation Audi 3. 0-litre V6 two-stage turbodiesel engine. The new engine weighs 192kg, somewhat lighter compared to the previous version, and can arrive first come july 1st inside the newly facelifted A6 and A7 in 215bhp and 268bhp forms. This 380bhp prototype, however, is predicted to reach into production next year, possibly like the first-ever Audi RS diesel. Like a lot of today’s higher-end diesel engines, the new unit uses two-stage turbocharging. Small of the 2 is lighter and simpler to spin up, and it is intended to provide the engine more grunt at lower engine speeds. The bigger turbo takes over at higher speeds.

The engine we’ve driven here is, however, something of the landmark design in it uses electrical assistance to ensure small of the 2 turbochargers is spinning quickly enough to become active even at really low engine speeds. In simple terms, Audi engineers have added an electrically powered blower towards the engine’s induction system, which, at really low engine speeds, forces air straight into the induction system, spinning small turbo into life. This ‘e-booster’ is connected towards the engine’s intercooler on a single side and towards the induction system on another, pushing air with the smaller turbocharger impeller between start-up and 3000rpm. At higher speeds, the e-booster is bypassed entirely. The e-booster is likewise intended to keep your engine on boil on, say, twisty back roads. Typically with diesel engines, braking for any corner also slows the engine and bleeds off boost. This leads to slower acceleration from the same corner as the engine spins up enough to obtain the turbos back on boost. But fitted using this new e-booster, the engine’s turbochargers could be primed as the driver remains braking, to ensure that full torque is available virtually immediately the driver gets back upon the gas. Although Audi engineers experimented with turbocharger units that were driven directly by an electric motor, they decided to not pursue the planning since it resulted in extra inertia, which, ironically, slowed the turbocharger response times.

The e-booster is powered by its own 48v electrical connection, while the remainder of the car uses a conventional 12v electrical connection. What‘s it like? As you may expect with 553lb ft of torque on tap from just 1250rpm, this Audi RS5 diesel is bombastically rapid. We drove the car at Audi’s new short driver training circuit near Munich. Although this was quite a distance coming from the open road, the track’s very tight curves, which demand a good deal of braking and re-acceleration, were ideal for testing the ‘e-boost’ promise. We followed a hot RS6 pace car – driven by knowledgeable Audi driver – all around the track in an effort to give us some concept of how this RS5 prototype can do business with Audi’s fastest RS road car. Given by a standing start, the RS5 had the measure from the RS6 for the very first few seconds, until the RS6 pulled away. There’s little question that that it engine gets far from rest very quickly indeed. But after the wall of seamless torque never appear to let up. Left inside the automatic gearbox's ‘Sports’ mode, the engine never had an opportunity of revving out, not because the transmission’s brain wouldn’t allow it to – there’s little point in trying with torque peaking at 2000rpm and power at 4200rpm. Another section of the reason the engine responds less as a diesel could be that the crankshaft, conrods and pistons have all been redesigned to scale back weight. These reciprocating parts really certainly can be a claimed 20kg lighter than normal. That’s plenty less mass to quicken and decelerate. The promise of massive pull being instantly on tap while you pull from slow corners is absolutely upheld. On six quick-ish laps, the engine was never left floundering for instant pace. Indeed, this engine drives hard sufficient to possess the torque-vectoring rear differential working right as much as the point it needs to let the rear wheels slide just a little. Though I’m sure purists will say the car’s dynamic performance is ‘artificial’, this Audi RS5 doesn’t understeer. The steering weight remains constant even beneath the hardest cornering and – importantly – It‘s relatively simple to drive hard.

 Should I buy one? You can’t – yet. As the Audi engineers on hand during our test were tight-lipped, I’d expect this engine to become offered some time next year. Additionally it is prone to appear in RS form because of the undeniable fact that the ‘diesel-ness’ of the unit is almost entirely eliminated, thanks to some mixture of e-boosting, its pretty free-revving nature and also the artificial sound generation from the exhaust system. The question that hasn’t yet been answered is why RS customers – who presumably aren‘t too sensitive to petrol prices – would want to purchase a diesel-powered car. The Audi engineers I spoke to remain very bullish on the longer term of diesel and suggest that oil-burning remains the supreme motive power for long distance, high-speed, motorway journeys and cross-continental drives. Moreover, after winning Le Mans with diesel powered sports cars, Audi finally includes a diesel engine good sufficient to put inside a future R8. Audi RS5 V6 TDI-e prototypePrice na ; 0-62mph ‘under 4secs’ ; Top speed 174mph (limited ) ; Economy n / a ; CO2 n / a g / km ; Kerb weight n / a ; Engine V6, 2967cc, twin turbocharged with electric booster ; Power 380bhp at 4200rpm ; Torque 553lb ft at 1250-2000rpm ; Gearbox 8-spd torque converter automatic Audi RS5 V6 TDI-e prototype first drive review