Tires

[PeterC4]

I have cleaned up my 2000C4 after it being in low use mode for the winter. I've only owned it 6 months. In the winter I drove it on clear days only and infrequently. Well, I had noticed the car was tracking to the right slightly and a very slight shimmy at higher speeds. I checked the tire pressure and sure enough, all tires were at different levels and lower than the recommended pressure. I adjusted all of them to recommended pressure and now it tracks straight. The shimmy is gone too. I can understand it tracking straight, but the shimmy gone? Don't get me wrong...its great, but I've never experienced that "fix" before. Anyone else experienced that?

I have stock 17's, relatively new Pirelli PZeros.

Edited April 19, 2005 by PeterC4

[Dr. Carrera]

Peter,

I've never experienced that before - my 911 never get's a chance to stay in the garage more than 2 days :drive: . On your question, in view of the a-typical weight distribution of a 911, the specific chassis and suspension set-up it is normal that unproper tire pressure has that much impact.

Happy driving!

[Danyol]

When I used to take long overseas trips (2-3 months +) for business there were a few things I did before putting my car away.

For one I would put my car on axle stands. Having weight on the same area of a tire would eventually cause it to be out of round, especially if they went flat. Taking the weight off the suspension and immobile bearings also kept these in good shape. The other thing I would do was to put the battery on trickle charge at very low current. Lastly I would cover the car in a simple white cotton cover (Don't forget to take the handbrake off). When I returned, my car would be ready to go in a short time and act like the day I left. Some folks I knew used to drain the fuel out of the car during the winter, put oil in the cylinders and used a rod to depress the clutch pedal (to prevent seizing). I never went that far.

Luckily I don't have to be away like this any more & get to use my 911 as a daily driver. The car is happy this way (and so am I) :) :)

[PeterC4]

After doing a little research, its amazing to learn just how much impact tire pressure can have on the handling attributes of any car, let alone a C4. Significantly under/over inflated tires will have a material impact on handling. According to Bridgestone, an inflation mismatch greater than 5 psi means that two tires can be significantly different in circumference. In a dual assembly, like a truck, the larger tire will literally drag the underinflated tire. So depending on just how much the 4wd system is activated, an underinflated tire can have quite an impact.

I'll be using the pressure guage more regularly from now on. ;)

[PeterC4]

Well after driving around for a while the dreaded vibration was still in the steering wheel, exhibited at higher speeds. Sure enough it took two trips to solve. An out of round tire in the rear, fixed for free and I paid for the other one - so I have two new ones. And then the front forced balanced, for the second time - for a nominal amount. Finally....got it driving right. For those with similar problems, you've got to be persistent.