If you've been watching Drive you'll know that there's a brand-new Audi RS5 in the wings. Due here around November this year, it uses a smaller, V6 turbocharged engine rather than the normally-aspirated V8 of the model we first saw here in 2010 (and was discontinued about two years ago).

The move to a smaller-capacity engine, of course, is all about efficiency and chasing a smaller fuel-consumption number rather than short-changing Audi customers in performance terms. Beyond some other mechanical changes, the new car retains the spirit of the superseded one, including the fact that it offers a sleek looking coupe with huge performance.

The thing to know about cars like the RS5 is that they trade on their fashion-status. Which means that last year's model is, literally, just that?

This isn't just an Audi thing; it affects every sporty, fashion-accessory car ever made, but it also means that the superseded car can be relied upon to drop some retained value fairly quickly as a result of a new, must-have version. And that's terrific news for those of us who like our cars the second time around.

What you're looking at essentially with the previous model RS5 was the A5 coupe body (there was also a convertible version, but the coupe is our pick) with Audi's 4.2-litre V8 engine and a seven-speed double-clutch transmission driving all four wheels via the most sophisticated version of Audi's Quattro all-wheel-drive system.

Power was a stirring 331kW, acceleration was phenomenal and the grip and the car's cornering were tremendous thanks to that all-wheel-drive grip.

If there were any dynamic grumbles it was that the engine could feel like it as lacking a bit of torque at times and needed to be wound up to really deliver. Among true sports-car fans, that's all part and parcel of driving such a thing, but others could feel a little frustrated at having to work the engine hard so much of the time.

Okay, we're splitting hairs here, but it remains that one of Audi's biggest claims for the new RS5 is that the new, V6 turbo engine bulks out the car's torque by a full 170Nm. The new unit also uses less fuel and contributes fewer tail-pipe emissions, so it's a good example of a technological advance.

But the one thing you won't get with the new model is the fabulous V8 soundtrack of the previous car. And in such a sensuous car as the RS5, that's got to count for something.

In any case, the new car's projected $160,000 price-tag towers over the numbers now being asked for the previous model, and a pocketful of change from the deal has got to be a good thing too.

When you're shopping for an RS5, you need to keep in mind that this is a car that uses the same engine as the V8 version of the R8 supercar, so there's quite a bit going on in a mechanical sense. Not the least of that is the transmission which, as a seven-speed DSG, demands a close check before parting with your dollars.

Any pre-purchase inspection (and we'd recommend an independent test with any car costing this sort of money) should include a proper diagnostic check of the transmission, because if it lets go it'll cost plenty to fix. The diagnosis should include a general health check as well as graphs that indicate the correct performance of the clutch packs.

But before you even get to that stage, a quick test drive will tell you whether the transmission is slurring, vibrating from a standing-start or losing drive in any way. And if any of those conditions exists, you could be looking at a very unwell DSG gearbox. Proceed with caution.

Another problem that seems to affect a small percentage of RS5s is that of carbon build-up on the engines valves. The trade is split down the middle over the cause, but it's either excess oil vapours being recycled into the engine or the fact that the V8 uses direct-injection technology. It's probably a bit of both.

In the first instance, you'd want to check that the engine's crankcase ventilation system is working properly and that the engine is not re-breathing too much oily gas in the name of emissions control. The other theory is that, unlike a port-injected engine where the fuel is sprayed on to the back of the intake valve, cleaning it, the direct-injection design avoids this and the carbon builds up as a result.

That said, the Audi V8 is hardly the only direct-injection engine in the world these days, yet carbon build-up seems to crop up when the V8's inherent problems are mentioned.

Symptoms that this build-up has occurred include an engine that is hard to start, runs or idles unevenly and is lacking power. In some cases, the build-up is enough to convince the on-board computer to illuminate the 'check engine' light on the dashboard.

The best advice we've heard in avoiding carbon build-up is to use the old 'apprentice tune-up' which involves throwing the keys to the workshop apprentice and have them thrash the car for 20 minutes. And it's not as silly as it sounds: A good, hard drive can help avoid things like carbon build-up in modern engines.

The only problem there is that with those 331kW on board, where on earth can you legally and safely let an RS5 off the leash for half an hour?

Our rating: 3.5/5

Nuts and bolts

Engine/s: 4.2-litre V8 petrol

Transmissions: seven-speed dual-clutch auto

Fuel economy (combined): 10.5L/100km

Safety rating (courtesy of www.howsafeisyourcar.com.au): Not listed

Likes:

• Huge performance.
• Lovely soundtrack.
• Great looking coupe.
• Classy and comfortable.

Dislikes:

• Expensive then and now.
• Tight in the rear seat.
• Adaptive suspension doesn't always strike the right balance.
• Doesn't look too different from base A7 coupe.

Competitors:

BMW M3 Coupe – Before the M4, BMW's high-stepping two-door was still called an M3. V8 power made for lovely noise and handling is race-track stuff. Like many non-turbo engines a lack of efficiency killed the idea. 4/5

Mercedes-AMG C63 – The last of the C-Class AMGs to use the non-turbo, 6.2-litre V8 will be collectors items sooner rather than later. Booming V8 was fast and huge fun. Watch out for thrashed or modified examples. 4/5

Jaguar F-Type – the latter-day E-Type (or so Jaguar would have us believe) is actually a very accomplished coupe. Two seats only, though, but don't discount the V6 version just because there's a V8. 4/5

What to pay (courtesy of Glass's Guide):

Model       Year        New                Now

RS5         2010        $175,300        $54,100

RS5         2011        $175,300         $62,600

RS5         2012       $175,300         $71,700

RS5         2013       $161,000         $83,300

RS5         2014       $155,900         $94,300

RS5         2015       $157,900         $102,600

RS5         2016       $157,900         $112,800