jar2000

You need to run high pressure 39-41 front & 37-39 back and the car will track straight.

GR8WHTLEX

I discovered the same thing. I recently bought a set of Toyo T1-S tires (great tires by the way). The installer inflated them to 40 psi which I questioned. He said that with the low profile tires, you need to inflate them higher than normal tires or you will experience the "bump steering".

My car is tracking perfectly straight now where previously it really required a concentrated hand (sometimes both hands) to keep it from following the grooves in the road.

eddiegs300

I am experiencing similar problems with factory 16" wheels and tires. Currently have 34lbs in all 4 tires. Any suggestions besides adjusting the tire pressure?

jar2000

You Need 36lb in the front 34lb in the rear

GS430 GUY

I just go with 36-37 all around on the 17's. Seems to put the drifting to a minimum but I still get it from time to time on the bad roads here in NY, like the LIE. On my 16's for the winter I go with 35-36 lbs all around, that works best on the 225/55 tires from my own experience.

TIKTIK11

whats pressure for michelin pilots on stock 17's?

lexguynj

Wow this is getting up there in PSI to like Mountain Bike Tire pressure!

But all of you here have hit on a great point, you have to up the PSI in these stock 17" tires. I remember being at your normal 32 PSI and the steering would wander all over the place as well as vibrate even on a smooth service.

Increasing the PSI on the tires to 36 significantly decrease this problem, but it's still there.

However 39-40 seems very high, but it if works even better, I'd do it. Why can't Lexus give us some suggested PSI for these 17" tires?

TIKTIK11

anyone know the correct pressure for michelin sports on 17's?

mooretorque

lexguynj, 40 is high. But that's what I've gone to to minimize the tramlining that the GS suspension is so prone to (granted this is also a low profile, wide rim issue, suspension design plays a big part). It's also a tread pattern issue. Some are less prone than others, but you can't (or I can't) tell by looking which is better and which is worse.

I ran 'em up to 37# with some decrease compared to the 35# I had been running, os I tried 40# and that's even better. Not perfect, by any means, but acceptable.

As far as Lexus' recommendations, look on the inside back cover of your manual. Also on the rear sheet metal of the drivers door frame, just below the beltline/B-pillar. As follows:

30/30 (f/r) for 215/60R16, add 13# for sustained speeds over 100mph
32/32 for 225/16R55, add 12# for sustained speeds over 100mph
33/33 for 235/45R17, add 10# for sustained speeds over 100mph.

TIKTIK, I'd start off with pressures Lexus published for the Bridgestones, and then adjust based on tramlining and handling. The numbers shouldn't be too far off even if Michelin recommendations are different......wouldn't expect them to be too much so.

bitkahuna

iTrader: (20)

All car manufacturers in my experience give recommended pressures that are too low. They do this so you'll think the car is more comfortable.

I run mine at 36 but may try 38 or more soon.

twenty1

If I go to 37# for air pressure all around, won't that cause uneven wear on my tires??? (By the way, I still have the stock 17's, though I'm probably gonna upgrade to 18's)

KNKGS400

i done 37 psi with my 17 and no problem so far, don't see why you would have uneven wear if your properly having all the psi the same>?

whitels

I run 39 Front and 37 Rear on Dunlop SP Sport 5000, 17s. No probs.

engin_ear

iTrader: (1)

mooretorque:
What is it about the suspension design that causes this??? It seems to be a Toyota trait - my 1988 Supra does the same thing...
can this be fixed with suspension mods???

Jerry.

mooretorque

engin_ear, I'm not enough of a suspension guru to answer that one. T/L isn't the only mfgr that has the problem, though. And really, it's probably better to say that low profile tires are more responsible and that suspension engineering is necessary to minimize or eliminate it.

The GS is very alignment sensitive and any deviation from optimum probably worsens the tramlining. As far as suspension changes, I just had L-Tuned springs and shocks installed (which also involves re-alignment) and the car is definitely tracking better than before, even tho the techs decided to drop my tire pressure from 40 to 35#. But certainly it's not completely eliminated. I'll post if/when I come up with more/better solutions.