Just logged in for the first time in ages, and read the article and thread comparing the M3, M5, RS4 and RS6. Since I've had the opportunity to encounter both the RS4 and the RS6 on German Autobahns, I thought I would chip in with an Alpina perspective.
B12 6.0L vs. RS6
A few months ago, I ended up behind a silver/grey RS6 Avant when entering the eastern section of the Berlin ring road (predominantly three lanes with several non speed restricted sections). It was a warm and sunny Tuesday about an hour before noon, so traffic was not too bad. The RS6 wast cruising in the left lane at around 160 kmh. I accelerated to catch up with him, and when he noticed me he also accellerated. We did a few runs up to between 200 and 220 before being slowed bown by traffic. Each time I had the feeling that he was not pulling away (as I would have expected), but rather that, if anything, I was closing in ever so slightly. We then got the first opportunity for a longer run, and it became apparent that the B12 was gaining on him. He moved over into the centre lane, and I passed him at around 250. The B12 pulled steadily ahead, and at 270 - 280 there must have been a couple of car lenghts between us before traffic slowed us down again. The road cleared up again, and we got to to a couple of long runs with the B12 ahead. Each time the B12 pulled away at higher speeds, I had over 300 on the needle on two occassions and the Audi was then a few car lengths behind. He did appear to be going almost as fast though, so I assume that the 250 speed limiter had been removed and that he was accellerating fully.
In total, we "raced" for some 60 - 70 kilometres (about a quarter "lap" of the Berliner Ring), though we never accelerated from speeds below 150 kph, where I'm certain the Audi would be much quicker than the heavy B12. (Alpina state 6,0s for 0 - 100 whereas the Audi clocks at around 4,6s if I remember correctly).
The RS6 is supposed to have 450 Hp and 560 Nm against the B12's 430 Hp and 600 Nm. I don't quite remember the influence of 4WD on high speed performance. Isn't it something that the transmission "eats" more power, but that there is less rolling resistance since all four wheels are driven? Anyway, Alpina claim a top speed of 291, and I believe I read somewhere that an unlimited RS6 goes close to 300.
All in all, I am surprised that the RS6 could not quite keep up. Could this have been a weak specimen, or might it be that Audi generally tend towards the optimistic side in their performance claims?
At least, for a while I felt good and forgot about feeling irrational and stupid for spending too much on what is basically just a travel tool anyway...
Alpina B10 V8 vs. Audi RS4
Last autumn, on a drive from Venice to Berlin, I had the pleasure of following an RS4 from Dresden to Berlin (over 150 km). We basically went full throttle all the way, and I saw 280 - 290 on the speedometer several times. Just as with the RS6 we were never a speeds much below 150, but ,unlike the RS6 experience the B10 could not gain on the RS4. I would say that the cars were very even, possibly that the RS4 was a fraction quicker.
Alpina state 347 Hp and 480 Nm for the B10 vs. the RS4's 380 Hp and 440 Nm.
The B10 possibly had a slight aerodynamic disadvantage due to an exploded sun roof...
Has anybody else had the experience driving at around 250 kmh with the glass sun roof tilted when a rock/pebble hits the glass? BMW in Munich claim they've never heard of it. What happens is quite spectacular! The sound is DEAFENING, like a gun shot, and the glass breaks into small pieces, most of which are pulled up by the air pressure and disappear.
It took about an hour to locate a roll of duct tape in Austria, and another hour to apply it over what once was a sun roof. It looked quite neat since I managed to get some black tape that matched the car's colour. I guess the negative pressure on the roof must be quite significant at higher speeds, because upon arrival in Berlin, I noticed that the duct tape had been stretched and pulled into the shape of a large hump, like a little balloon almost. It can only be assumed that this negatively affected the aerodynamics of the car to the extent that the RS4 could not be humiliated...
As it later turned out, it could also be assumed by Polish custom officers that the hump was a clever stash for smuggled goods...
...where else would a hardened criminal hide his goods? Taping them on top of the car would certainly be a most cunning hideaway that few members of the law enforcement community would ever find. The elite Polish border guards are a clever breed though. Can't wait til May 2004 when most of these geniuses will either be unemployed or have to move to the Russian border. Revenge, ha!
What's the point of sharing all of this?
Just to suggest that you think twice before driving at high speed with a tilted sun roof.