Tramlining with wider tires?

450knotOffice · 450knotOffice's Garage

Well, I finally replaced my worn out, almost slick, rear S-03's with brand new ones. I had the stock 225/50's on 8's and went with 245/45's on the same rims.

I am now suddenly noticing that the car seems to want to follow all the grooving on the freeway. The car just wanders a bit in the lane. Would this be considered a normal consequence of replacing worn out, almost slick rubber for new tires with full size tread blocks; and would going from 225's to 245's also magnify this tendency?

I am curious about this because I've always been able to drive the car on our SoCal freeways with just one finger on the wheel without the car showing a tendency to follow the grooves. Now, all of a sudden I have to pay a little attention as the car seems to want to follow the grooves a bit.

If the wider tires are the culprit then I've got to ask how the heck you guys with 315's in back deal with the tramlining. Jeez.

Oh Haha · 11-14-2005, 10:36 AM

It may just be a bit of tread squirm. New tires need to have the newness driven off. It should only take a couple hundred miles to get 'em broken in. I just had new tires installed on my daily driver Vibe and it has some weirdness to it now.

ken_xman · 11-14-2005, 10:42 AM

my yoko's on 17" FM-10 wheels, did just that for the first 100 miles.
It now feels normal again.

87coupe · 87coupe's Garage

Did you only replace the rear tires? Having a mismatch between the front and back will cause the "Tramlining". Normally this is when you have two different models of tire front & rear, but AFAIK it could happen w/ a new/old combo of the same tire model.

Reminds me of Days of Thunder, "I put a special match set of tires on there Cole, you can hold it!" lol, sorry.

DW SD · 11-14-2005, 10:52 AM

My car tramlines a bit. Done that since the tires were new with no definite change. I don't need two hands to drive it though. It does stay straight, though. I'd say it is relative minor for me. Tire pressures, alignment settings, camber could all have an impact, I believe.

Doug

450knotOffice · 450knotOffice's Garage

I just talked to a guy who's been a Porsche racer for 25+ years who owns his own Porsche repair/race shop and he seems to feel it's normal. New tires. Tread squirm. He told me the tires will wear in or I'll just get used to it.

On a related note, the rear tires are at 36 psi cold. This is about what I had in my 225's. What kind of pressure should I be running in these 245's? The same? I've been told I might want to increase the cold pressure to 40 or so to stiffen up the sidewall a bit.

DW SD · 11-14-2005, 12:01 PM

I'd guess 32 upfront 34 in the rear would be close. That's what I had my radials at on the last track day. I bet you could run a bit softer for the road. Maybe 30 & 32. My car is lighter, though by a good bit.

Weight plays a role. Since these cars are split 40 / 60 or more usually you run more pressure in the rear. Two pounds seems the # I've always heard. I'm no expert.

Doug

450knotOffice · 450knotOffice's Garage

Yea, Doug. Your car is 390 pounds lighter than mine. I've been running 32 up front and 35 in back with the old 225's. I've got the rears at about 36 right now.