Audi S4 VS Alpina B5

The S4 is terrific fun. It's that simple. The new engine is an absolute belter, with all 500Nm of torque available at just 1370rpm. Lag is almost indistinguishable as the turbo spools up and rockets you along to 100kmh in under five seconds, that huge half-ton of torque sweeping you down the road.

With dynamic mode switched on, the car muscles up with firmer suspension and a slightly growlier exhaust. The steering really weights up, too, which takes a little getting used to after the lighter, friendlier setting in Comfort mode - thankfully you can set up an individual mode to dial the assistance back in while everything else is set up for go-fast.

The key to the fun is the rear-biased quattro system - while it's never going to match the purity of BMW's rear-wheel drive 340i, what you lose in steering feel and ultimate adjustability, you gain in off-the-line and mid-corner grip its German rivals could only dream of.

Going fast in an S4 is easy, leaving you to concentrate a little more on your line and gear selection, listening to the distant bark of the engine and the occasional turbo whistle. All of this is purely down to driving taste, of course but the point is, the S4 offers something a little different to the other two. 

For most of the time the S4 defies its 1700kg-plus weight but there is the occasional hesitancy when changing direction through a challenging set of bends, as though the front tyres (245s all around, if you're interested) want to scrub and the quattro system makes a quick adjustment to stop it happening. You don't feel that's what's happening, of course - Audi Sport is better than that - but it's part and parcel of all-wheel drive. It takes a lot to find understeer and for most people, that just won't ever happen.

Further confidence comes from the terrific brakes - 350mm up front and 330mm at the rear, the big forward rotors are gripped by six-pot fixed calipers. Performance is epic and in hard, fast driving they stood up to a fair amount of punishment without fading.

The ride is excellent in all modes, which is quite an achievement given the fat rubber and big wheels, although big bumps at speed make a huge metallic thunk without actually upsetting progress. The eight-speed ZF is brilliant as always and unless you're really motoring, you don't even need its sport mode, which brings impressively fast and positive shifts.

The best thing is, if you don't look in the rear vision mirror, you can't really tell if you're driving sedan or Avant. That might be because it's quite absorbing on a launch drive, but I couldn't split the driving experience between the two.

The only black marks I could easily identify on the S4 is tyre noise on some surfaces and perhaps the steering could be a little more lively like its competitors.

Ok, stay with me here. For this next bit you'll need a fresh egg, a lounge chair, and it might be a good idea to have some plastic bags and carpet cleaner on hand.

First, in front of the lounge chair flatten out the plastic bag and place the egg on it. Next, sit down on the chair and very carefully rest the ball of your foot on the egg with as little pressure as humanly possible.

This is exactly how little force you need to apply to the go-pedal of the B5 to accelerate from a standstill to 60km/h in about five seconds.

If anything sums up the driving experience of the B5, it's that sense of effortlessness.

Stomp on that accelerator, and you'll be shot to 100km/h in 3.5 seconds, without a hint of broken traction thanks to the all-wheel-drive system.

The ride should have been terrible on 20-inch wheels shod in low-profile rubber (Pirelli P Zero 255/35 front, and 295/30 rear), but the Alpina-tuned air suspension is close to miraculous in the way it cushioned and censored the potholes out of Sydney's worst roads. Yes, it can be a touch floaty, particularly in the Comfort Plus setting, but this is benchmark-setting stuff for a comfortable ride.

Don't expect this beast to roar. Unlike the M5, the B5 gets its work done without deafening everybody around it. Sure, the B5's V8 sounds amazing when you push it, but it's not brash, not loud and not lairy. Buy an M5 or Mercedes-AMG E63s if you want to be heard half a block before you get home, but you won't get that with the B5 and its exhaust system.

The B5 also handles well, but I have to say the engagement factor is low. I piloted it effortlessly through the twists and turns of my country test circuit and roads which normally have me grinning like a maniac behind the wheel had me feeling a bit disconnected in the B5. That air suspension, the numb steering and pedal actions make it difficult to ‘feel' the road.

It's highways where the B5 is a king, but even at 110km/h there's the sense that this car is still fast asleep and won't get out of bed for anything less than 150km/h - making it perfect for Germany's autobahns, but maybe not for here in Australia.