granracing

I was looking at AutoTrader and other sites (I really need to stop torturing myself until I’m ready to buy a 996 later this year!) and saw several Carrera 4 996s for sale at quite reasonable prices. Some are even less expensive than similar condition and millage RWD versions. My initial thought was to stay away from a C4S since it has more components and therefore more that could go wrong with it. I also have fun driving RWD in the snow and wet and can’t see myself specifically looking for a C4S. Is there any additional maintenance that needs to be done with the all-wheel drive systems? Any known issues and how reliable are they? Is there a way to manually turn the all-wheel drive off? I couldn't seem to find this info in the books I have or searching threads.

Ubermensch

You need to change the oil in the front transaxle but that's pretty infrequent and not a big deal. I've never really heard of many people having problems related to the 4wd system. I'm just about to hit 100k miles and haven't had any problems with it.

There is no way to turn off 4wd.

For me, the extra confidence in bad conditions is well worth it.

pongobaz

Yeah, and only every 90k miles. +1 on the confidence thing and the look of the 996 C4S is special imo.

redridge

the only problem Ive heard is with the Turbo awd.... when people start modding their cars to like 600+ hp... the the awd become unreliable.... the viscous coupling just spins till the power lessen.

For the c4 or c4s.... its a simple setup that is designed for stability rather than an AWD function. You can still drift with the c4s and drive similar to a c2.... I would say the steering feedback is better on the c4 than a c2 since the steering is attached to the front wheels. The diff couples the power from 5%-55% (or something like that) so it is always on but the power delivery is based on rear wheel slippage..... no slippage means %90 of the power is to the rear wheels.

gota911

IIRC, the "percent of power to the front wheels" ratio varies between 5% and 40% on the C4/C4S, which means 95% to 60% of the power goes to the rear wheels.

However, I could be wrong because I did NOT stay at a Holiday Inn Express last night.

Dennis C

I haven't yet taken delivery of my Carrera 4S (a little more than a week to go)... so I can't give much commentary there. Is the AWD system there similar to the Cayenne's AWD system? I can tell you this - the Cayenne will gladly throw the rear end out on slippery streets, even with PSM active. It clearly favors the rear wheels. The fronts eventually kick in, but it is not instant response. I wouldn't call it an excellent winter vehicle, especially not with the 20" wheels...

Ray S

The system cannot be turned off and from what I have read it is not particularly problematic. I'm personally not a big fan of the AWD system because of the parasitic hp loses, extra weight, and additional understeer the system delivers (plus I think it saps some of the RWD fun in these cars).

On the positive side I have used a C4 on an wet autocross circuit and it performed well.

From a looks standpoint, I think the C4S is the best looking (non turbo) 996. The wide hips and turbo front make for a sharp looking 996.

Good luck

Meister Fahrer

Yeah, I think the only really problematic awd was the 964, what do they call it something like "NASA AWD" because of the tremendous complexity and costly repairs....

The thing I considered was the additional weight, but having a bit more weight up front on a rear-engine car is not a bad thing....

zroadhouse

I can attest to the fact that the AWD system does not get in the way of "rotating" the car. I have a nice 110 degree right hand turn that I love to take with a little speed (if there is no one else around). A little throttle in the turn and the car just rotates. I love it!

Edgy01

The 4WD of the 996 and 997.1 models is very simplistic. It's a viscous clutch that is pretty simple, and thus a LOT less expensive to maintain. To be perfectly frank, the BIGGEST selling point for the 9964S is the LOOK. Everyone thinks that the 9964S is probably the best looking 996 ever produced. This is what keeps its prices higher.

It hasn't been until now, on the 997.2 AWD cars, that they have entirely redesigned the AWD system away from the viscous clutch and more like the 959 and the early 964s. When Porsche discovered how much trouble and expense was involved in maintaining the 964 Carrera 4s, they went back to simplicity itself, with the viscous clutch (like in the Vanagon Synchro).

zroadhouse

Any links for reading information on the the AWD system in the 997.2?

jyoteen

on the track, I have no issues with AWD whatsoever. in fact, on a wet skidpad at Laguna, I had no problems causing fuel starvation with the *** end hanging out and a rooster tail.

67FJ45

+1 on the looks. I think the C4S is the best looking 996 of all. I chose a C2 over the C4S because I wanted low mass for the track.

Yup. On the track, I recently followed a friend and watched him rotate his C4S 180 degrees.

Ray S

Same reason for me, but they do look sweet.

russo

I prefer the RWD over the AWD, it feels more nimble.