Interesting comparison here by Sport Auto between the 991 Carrera S which is rear wheel drive and the 991 Carrera 4S which is all wheel drive. Both cars have the same 3.8 liter flat-6 engine with 400 horsepower. The test cars are both manual so it is interesting to see how the addition of all wheel drive changes things. The difference in weight between the two cars just 29 kilograms (just 63 pounds) which really is not much additional weight at all.
The acceleration figures in every test favor the all wheel drive C4S. Even up to 124 miles per hour the lighter rear wheel drive Carrera S just can not catch it even in the dry. The C4S acceleration advantage obviously gets much larger in the wet and in the snow.
It is not just acceleration that favors the C4S thanks to traction but the track times as well. The Hockenheim laptime for the C4S on a dry track is faster as well, considerably by 3/10's. Check out the full data below.
Porsche 911 Carrera S vs. 911 Carrera 4S
Both with manual gearboxes.
Dry - Tyres: Pirelli P Zero - Weight: 1505 kg vs. 1534 kg - 0-40 km/h: 1,5 s vs. 1,2 s - 0-100 km/h: 4,7 s vs. 4,3 s - 0-160 km/h: 9,9 s vs. 9,4 s - 0-200 km/h: 15,1 s vs. 14,6 s - Braking (100-0 km/h): 33,3 m vs. 33,2 m - Hockenheimring: 1.12,0 min vs. 1.11,7 min
Wet - Tyres: Pirelli P Zero - Weight: 1505 kg vs. 1534 kg - 0-40 km/h: 1,9 s vs. 1,4 s - 0-100 km/h: 5,2 s vs. 4,8 s - 0-160 km/h: 10,5 s vs. 10,1 s - 0-200 km/h: 15,7 s vs. 15,2 s - Braking (100-0 km/h): 38,9 m vs. 38,6 m - Hockenheimring: 1.26,6 min vs. 1.26,6 min
Snow - Tyres: Michelin Pilot Alpin PA4 - Weight: 1513 kg vs. 1540 kg - 0-40 km/h: 6,7 s vs. 3,6 s - 0-100 km/h: 18,5 s vs. 10,9 s - Braking (100-0 km/h): 115,7 m vs. 114,5 m - Hockenheimring: 2.18,5 min vs. 2.12,4 min
It is not just acceleration that favors the C4S thanks to traction but the track times as well. The Hockenheim laptime for the C4S on a dry track is faster as well, considerably by 3/10's. Check out the full data below.
Now, now, lets not get too carried away! A difference of .3 seconds on a circuit where the lap for the cars in questions is approximately one minute twelve seconds is hardly a "considerable" difference.
Why do you think AWD is banned or not used in F1, Indy cars, or NASCAR?
It is not just acceleration that favors the C4S thanks to traction but the track times as well. The Hockenheim laptime for the C4S on a dry track is faster as well, considerably by 3/10's. Check out the full data below.
Now, now, lets not get too carried away! A difference of .3 seconds on a circuit where the lap for the cars in questions is approximately one minute twelve seconds is hardly a "considerable" difference.
Why do you think AWD is banned or not used in F1, Indy cars, or NASCAR?
Those are professional drivers though... put non-professionals in and I think you'd see an even bigger difference. To make a RWD go fast around a tack you need be somewhat of a drifter, with an AWD you just steer and stomp (yes oversimplified explanation but largely true).
And why is AWD not permitted by the class rules? I don't really know, but I suspect the biggest part of it, is the history and tradition, also part of it is the desire to keep costs controlled.
