I experienced difficulty going up my drive way yeserday. I have big patches of snow and ice along the way.

Does the Porsche 4WR works when only one wheel has traction? I.e. that it shifts power between left and right instead of just front and rear?

Thanks.

 

the 4WD can only do so much. if the ice and snow is too much, it won't help at all. you might have to shovel "gasp!" the driveway.

sometimes it helps to BACKUP the driveway (backwards) instead of going up forwards.

try it.

 

Uhh...

Why would backing up the driveway help on a tail-heavy 911 ??

I see how that would work for a front heavy, FWD car...but for the 996TT?

Maybe I'm missing something....

 

Try getting some winter tires - if you were trying to drive on ice and snow with the stock Pirellis that is the cause of alot of your headache. I purchased the Dunlop Winter M2's for my 996TT and they perform extremely well in the crappy weather. As said before though - the car can only do so much. Good luck. T2

 

If you're starting from a standing start or going extremely slowly, sometimes the traction control applies too much brake or kills too much power to gain momentum. I've found that in those conditions, it's helpful to switch off the traction control to get the tires spinning, then turn it back on once you have a small amount of movement. AS

 

Switching off the traction control made a lot of difference. Thanks a lot.

Do you all purchased different wheels for winter tires or just mount the winter tires on the stock wheels?

I couldn't find any 295/30 R18 winter tires on tirerack.com.

Thanks.

 

Shan,

I mounted my winters on another set of hollow spoke stock rims - make it easy to swap them myself in the spring.

A magazine called Christophorous did an exhaustive analysis of winter tires for all the current Porsche's. They recommended the Dunlop SP Winter Sport M2's for the 996TT. 225-40-18 for the front and 265-35-18 for the rear. I have them, got them from Tirerack for about $725 delivered, and they perform great in the snow, wet and cold. I highly recommend them. You may be able to get them to mount them on some cheap aftermarket rims for looks or just use steelies - it makes swapping much easier.

If you call Tirerack they will have the sizes in the computer for the car.

Let us know how you make out. T2

 

BTW, there are big differences in 4wd systems. Some systems, like what you would find on a old S-10 pickup will spin only 1 wheel on ice... so much for 4 wheels driving. Other system, like the older Range Rovers, Land Cruiser, etc. allow you to manually lock all 3 differentials and spin all 4 wheels no matter what. The newer high end off road vehicles tend to use computers to control the traction. Some use lockable diffs, others use the brakes to even out wheel speed and send power 'from the wheels that slip to the wheels that grip'. I am not sure what Porsche uses in their cars, I do believe that with the advent of PSM, we all lost the limited slip in the rear so it is likely all open diffs and I'm sure PSM is not designed for the snow. That would lead me to believe the Anewer WD Porsches are not the ultimate performers in the snow.

 

I'm not sure that I would agree that "PSM is not designed for the snow". It seems to work fine. Anybody have any facts on that? AS

 

[quote]Originally posted by adrial:
<strong>Uhh...

Why would backing up the driveway help on a tail-heavy 911 ??

I see how that would work for a front heavy, FWD car...but for the 996TT?

Maybe I'm missing something....</strong><hr></blockquote>

It's the Porsche equivalent of putting the car in low-range... Least amount of force to the wheels per unit of pedal input... hence least likely to over power the traction of the tires.

Also -- it makes sense to turn off PSM at times. PSM is designed primarily to return or keep a car at a controllable state -- but when you are dealing with a snowy driveway that could mean keeping the tire with the most grip from grabbing too much... If you think about it, what works on snow at 5mph to get you over the one tough patch (one wheel or two taking over) is exactly what can kill you at 100,