sambaek

Hi, I just bought a 2001 996 C2.
This is my first Porsche.
Everything is good, except on free way, around 65mph to 80mph.
Car swerves when the road have grooves or rough surface.
I have read a Excellence Magazine about Porsche.
Interestingly, In one of the article about new 997 GT3, one paragraph say;

It's obvious that Weissach has made a real improvement in straightline behavior at freeway speeds; the old GT3's tendency to tramline and follow grooves in the pavement has been banished.

Is this sweving on straight line driving on 2001 996 C2 NORMAL?
for your info, I do have 18" GT3 Wheels with 10 spokes.
Any of you have similar experience?

Dale Gribble

with the stock alignment/tires it shouldn't be very noticable. if you have an aggressive alignment (check ur camber) or your alignment is just off...this would exacerbate the problem.

nick49

On my 986 and 996 this is normal and is most noticeable as the tires wear. This will be readily apparent when traveling an interstate used heavily by large trucks and most likely non existant on flat smooth roads. It may be more or less noticed depending upon the brand and tread pattern of the tire used and inflation pressures used. My Lexus doesn't hint of this, nor does my jeep, but they have tires with tall cushy sidewalls where as the stiff low aspect ratio and wide tires on the P-cars made for responsive handling and road feel, do just that.

Fred R. C4S

FWIW

As this is a used car, and new to you, there might be an alignment issue. Take a look at the tires for uneven wear patterns. Every car runs a little bit of toe IN for stability. Race cars tend to run ZERO toe or a bit of toe OUT to increase the steering response of the car. A little toe OUT will make the car seem a little darty, and aggravate tramlining. If you have toe OUT get it fixed. You can ruin a set of front tires in a few thousand miles.

Cheers,

cdodkin

Tire make, wear pattern and alignment - all will effect tramlining

What tires do you have up front?

How's the wear looking?

Pugnacious P

From my experience with the bad highways we have in CT tramlining is normal and quite noticable even with a perfect alignment. My 996 does it and my Boxster did it from mile 12 on the clock. When I first bought it new, it acted as if it were in a groove on the highway on a patch of road I drive everyday and never had a problem in other cars and being a noob I had never heard of tramlining. I went to the dealer who checked alignment, and it still happened. I went to a PCA tech tactics when I was told its called tramlining and completely normal for the tires and widths the Porsches run.

sambaek

Thank you everyone for your kind comments and explanation.
I feel a lot better now.
I had suspected a wide and low profile tires and wheels.

This was a Certified Pre-owned Porsche and dealer installed brand new “CONTINENTAL TIRES”.
The dealer told me, these tires are Porsche approved.

Again, Thanks a lot for your good info.

ElTorrente

Tires alone can make a HUGE difference in tramlining. One brand to the next you'll see a difference. Of course there is also the alignment to consider. The two main things I worry about when researching/buying new tires is: Tramlining and road noise. Always look for these key things in reading reviews about new tires before buying them.

CosmosC4S

I do not think it's the brand of your tires, nor the alignment, IF you are tramlining on bad surfaces,
like as mentioned above, heavily used truck routes, where you have deep grooved surfaces.

It's definitely the wide tire width. I've been thru' that same thing, spent money to have things done, and finally learned it is normal for wide tires to behave that way. It was the same on all my other cars with wide tires.
On my Chevy S10 and Isuzu Axiom SUV, both with narrower tires, they ride thru' the same surface with no effect at all.

However, if that happens on a fairly smooth surface, then something is not right,
or this is when alignment, and different tire brands and tread patterns may come into play.

BlackCab996

When I bought my CPO car, it still needed an alignment and had a bent rim - I don't tramline now - fortunately the dealer picked up the tab on the alignment and the rims, as I raised the issue RIGHT AWAY - I suggest you let them know that you have a concern and have them check it out now...

QueenCityCarrera4

Exactly!!!!

Porsche_Smile

yes it 's normal... just got new wheels for my p car... what a difference...

Porsche917K

My C4S was really bad when I first purchased it. When I would try to change from the slow lane to the middle lane, the road would almost throw me completely through the middle land and into the fast lane! I was sure that if a cop ever got behind me, he would surely think I was intoxicated.

Since I have put on new tires it has improved greatly, but still a little tough on a heavily used freeway.

450knotOffice

Tires do in fact make a difference. My '84 Carrera tramlines pretty noticeably with my Bridgestone S03's, yet when I had a loaner set of wheels mounted with SP8000's (same size) there was almost no tramlining at all. The difference was very noticeable.

My 996 exhibits almost no tramlining tendency but I'm quite sure when I upgrade to larger wheels and tires with better tires (I have Yoko AVS ES 100's right now - hate 'em), I'll probably see some more tramlining.

CosmosC4S

Haha...I've used the AVS ES100's before, and I know what you're saying.
They wear fast and are noisy. But they do grip pretty good dry.
I wanted to get rid of it so bad at the time, I did lots of drifting to make full use of the rubber.