GS 300 Tyre Wear

[gwilymrj]

Hi,

I have owned a GS300 since new in 2006, and driven 15000 miles mostly long distance trips on M'ways and A roads. At its annual service Lexus Twickenham advised me of excessive wear on the inside of the front tryes. They suspected that the front wheels were out of alignment due to some road bump or mounting a pavement. I left for France the next day so I had the wheel geometry checked by a Lexus agent on arrival at my destination. By this time the tyres were badly worn and I had the dealer fit new Michelin Primacy tyres on the rear, moving the original Dunlop Sports to the front.

To my surpise the wheel testing showed more or lest perfect alignment, but negative camber on the front wheels both of which were outside Lexus's tolerance. They have adjusted the camber to -21' (left front) and -37' (right front), leaving all all other readings more or less unchanged.

I noticed from the Lexus Owners Forum that tyre wear problems were not unusual with the IS model, and it was even suggetsed that Lexus had historically appled incorrect settings, but I found nothing specific about the GS. One correspondent suggested that I contact you, saying that Tony from WIM was THE expert on all such matters! So here I am!

My questions are:

1) Is it likely that the negative camber on my GS was incrrectly set when I bought the vehicle in 2006, or it is plausible that somehow I have knocked both front wheels out? (There's no sign of damage to any of the wheel rims).

2) Are the new settings going to resolve the problem and give me decent mileage from my tyres (I am over 65 and my driving style is consistent with my age!). I am used to getting 30k plus from a decent set of tyres.

3) Is this likely to be a recurring problem and should I get the geometry checked on a regular basis?

4) Any views on Michelin v Dunlop? On previous cars (Ford, Peugeot, Citroen) I have always been very satisfied with Michelin, despite the premium paid on purchase.

 

Thanks in advance for any advice.

Gwilym.

[Tony]

Hello

 

Historically the GS has a stable chassis and the data suggested by Lexus is correct "BUT" not law.

 

To explain

There are to many variables to assume the target data covers all drivers, so a good technician should measure the chassis, look at the type of wear (camber-toe) then compensate accordingly.

 

Example

Today i had a Volvo V70 owner who has just ruined his second set of rear tyres.... The pattern of wear is toe so lateral across the tyre tread.

 

I measured the chassis and the rear toe was correct at +.5mm each side, so i adjusted the toe (out of spec) to 0. In 2000 miles time we will check the tyres again and see what direction the lateral wear is (if any) then fine-tune the toe to suit.

 

Your driving style is fine and you've done nothing wrong but the package Lexus gave you doesn't suit you.

[scorps]

Hi Gwilym, glad you made it on here.

[gwilymrj]

Hi Gwilym, glad you made it on here.

 

Thanks for your reply.

This is fascinating but very technical for a simple motorist like me who just wants miles of safe, comfortable, trouble free driving. What still bugs me is that I've never experienced anything like this before. Until now sensible driving guaranteed that you got 1000's of miles from your tyres.

Perhaps what I need to do is check the tyres on a more regular basis and get WIM to take a look at the car on the first signs of any more problems.

You didn't say whether the camber problem was likely to be caused by road bumps, or could there have been a latent problem when new?

Anyone else with similar problems?

Gwilym.

[Tony]

Hi Gwilym, glad you made it on here.

 

Thanks for your reply.

This is fascinating but very technical for a simple motorist like me who just wants miles of safe, comfortable, trouble free driving. What still bugs me is that I've never experienced anything like this before. Until now sensible driving guaranteed that you got 1000's of miles from your tyres.

Perhaps what I need to do is check the tyres on a more regular basis and get WIM to take a look at the car on the first signs of any more problems.

You didn't say whether the camber problem was likely to be caused by road bumps, or could there have been a latent problem when new?

Anyone else with similar problems?

Gwilym.

 

If the wear is sharp when you run your hand across the tyre then it due to the toe.... If it's smooth and confined to about 10% of the tyres total width then it's camber.

 

Road bumps "do not" put the Geometry out unless you hit them at 90mph, the criminal is the pothole.... Your GS obviously needs attention and it's probable once set you will never need to have this done again.