When the time comes to replace your tires, do you find...

Z4Rick said:
that your rear tires wear quicker than the fronts? I tend to be heavy on the throttle and light on the brakes, so I am not surprised particularly, but it seems pronounced on the Z. I also tracked the car 3/4 times last summer, but I think the front tires could last thru another set of rear Pilots!
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I recently noticed that mine are in serious shape on the inside edges. This seems to be caused by the camber in the rear. I also drive hard enough to cause this but it is ridiculous to wear out the inside edges,,it basically could mean that the inside tire on a hard turn is dragging the inside edge. I have done some set -up work in years past for tracking and autocross. Using a pyrometer the alignment can be set to wear evenly and this usually provides the best grip. I am going to have the rear camber set to -1 degree. We shall see.
If yours are wearing evenly, I would not worry about it. Most cars push (understeer) and therefore wear out the outer edges of the front tires when tracking. The Michelins may be doing a good job if they are not wearing out on the outside edge in front.
So are the rears wearing on the inside edge or are they wearing evenly?
 
extaz said:
Z4Rick said:
that your rear tires wear quicker than the fronts? I tend to be heavy on the throttle and light on the brakes, so I am not surprised particularly, but it seems pronounced on the Z. I also tracked the car 3/4 times last summer, but I think the front tires could last thru another set of rear Pilots!
Click to expand...

I recently noticed that mine are in serious shape on the inside edges. This seems to be caused by the camber in the rear. I also drive hard enough to cause this but it is ridiculous to wear out the inside edges,,it basically could mean that the inside tire on a hard turn is dragging the inside edge. I have done some set -up work in years past for tracking and autocross. Using a pyrometer the alignment can be set to wear evenly and this usually provides the best grip. I am going to have the rear camber set to -1 degree. We shall see.
If yours are wearing evenly, I would not worry about it. Most cars push (understeer) and therefore wear out the outer edges of the front tires when tracking. The Michelins may be doing a good job if they are not wearing out on the outside edge in front.
So are the rears wearing on the inside edge or are they wearing evenly?
Click to expand...

Hi, I don’t think it’s possible to adjust the rear camber down to -1 degree, I think the most it can go down to is 1.5 degrees?
Rob
 
Hi, I don’t think it’s possible to adjust the rear camber down to -1 degree, I think the most it can go down to is 1.5 degrees?
Rob
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I believe the minimum spec is 1.6 degrees for my car, now that you mention it. I will try to get it as low as it will go. Camber can also affect Toe which also can cause a lot of wear, so everything must be done properly and in the right order. Ageing springs and bushings and loaded weight also affect alignment. Be happy if your tires wear evenly. Most BMWs have quite a lot of negative camber in the back. It seems extreme to me because I don't see it on any other performance cars. The tires are expensive on a 35i and they can not be rotated. In any event the rears will wear out first because they put down quite a lot of power and also the skid control intervention will do some subtle braking. Power oversteer (drifting) type driving obviously is another cause.
 
flybobbie said:
Will be replacing my rear Goodyears soon. They have lasted about 20k miles.
Running at 42 psi they have worn in the centre slightly more than the edge. So will run 40 psi on the new ones.
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That seems high to me. I have 33 all round usually and mine wear fine. Bald in the middle is a sign of over inflation.

H.
 
Busterboo said:
33! :o E89? And your Porsche?
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No, just the M on 18's. I am sure the manufacturers recommendations are 33 on the rear and up to 38 at the front, fully loaded. Would have to check, as I am not near the car at the moment.

I would need to check the Cayman but after having brand new tyres put on at a specialist, they were 34 all round I think.

H.
 
R60BBA said:
Z4Rick said:
that your rear tires wear quicker than the fronts? I tend to be heavy on the throttle and light on the brakes, so I am not surprised particularly, but it seems pronounced on the Z. I also tracked the car 3/4 times last summer, but I think the front tires could last thru another set of rear Pilots!
Click to expand...

Surely this would be the same for all RWD cars and not just Zeds...?
Click to expand...

On performance cars, with ample HP and torque, I'd assume more HP equates to faster tire wear, but I had hoped the staggered setup might have evened out the wear. Ive been driving pickups and 4X4s for too long....and enjoy the Z's power too much!

I think its just part of the price to be paid for a "spirited" driving style....and I see little reason for change!
 
extaz said:
Z4Rick said:
that your rear tires wear quicker than the fronts? I tend to be heavy on the throttle and light on the brakes, so I am not surprised particularly, but it seems pronounced on the Z. I also tracked the car 3/4 times last summer, but I think the front tires could last thru another set of rear Pilots!
Click to expand...

I recently noticed that mine are in serious shape on the inside edges. This seems to be caused by the camber in the rear. I also drive hard enough to cause this but it is ridiculous to wear out the inside edges,,it basically could mean that the inside tire on a hard turn is dragging the inside edge. I have done some set -up work in years past for tracking and autocross. Using a pyrometer the alignment can be set to wear evenly and this usually provides the best grip. I am going to have the rear camber set to -1 degree. We shall see.
If yours are wearing evenly, I would not worry about it. Most cars push (understeer) and therefore wear out the outer edges of the front tires when tracking. The Michelins may be doing a good job if they are not wearing out on the outside edge in front.
So are the rears wearing on the inside edge or are they wearing evenly?
Click to expand...

They are worn evenly, and the front shows some wear on the outside edge, but its hardly an issue and a recent alignment may have corrected that....
 
33 psi think they would come off the rims!
Door sticker says 38F 42R RFT 18inch , but non RFT you become a test Pilot.

Got to order some rears now, got a slow puncture, the warning trigger at 38 when checked. Was reset to 42.
 
htzgPOm.jpg

I can't believe I went to the garage to confirm this. Cayman is 33 all round.

g7CeKft.jpg

Zed is 32 rear and just 30 at the front.
 


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They are worn evenly, and the front shows some wear on the outside edge, but its hardly an issue and a recent alignment may have corrected that....
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Thanks Rick that is helpful for my problem . Seems like you are doing very well especially with that much tracking. I may try the pilots as well.
 
Havard said:
htzgPOm.jpg

I can't believe I went to the garage to confirm this. Cayman is 33 all round.

g7CeKft.jpg

Zed is 32 rear and just 30 at the front.
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It's surprising people don't follow what it says on the stickers on their E89s.
 
flybobbie said:
It's surprising that the Z4 E89 pressures are much higher.
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What do the stickers say on the E89?

I assume the use of runflats has something to do with it or just a heavier car than the E85/86.

H.
 
Busterboo said:
Havard said:
flybobbie said:
It's surprising that the Z4 E89 pressures are much higher.
Click to expand...

What do the stickers say on the E89?

I assume the use of runflats has something to do with it or just a heavier car than the E85/86.

H.
Click to expand...

Just a heavier car.
Click to expand...
Weight cant have anything to do with it.
My X6 runs lower pressures than the Z4.
Unloaded the sticker on the X6 says 2.0 bar front and 2.2 bar rear
The Z4 is 2.5 bar front and 3.0 bar rear.
I have just removed the rear tyres from our Z, GoodYears, and they have been run at the recommended pressures on the door jamb sticker for their whole lifespan. The tread wear was even right across the tread and lasted around 25,000 miles.
 
Busterboo said:
Havard said:
flybobbie said:
It's surprising that the Z4 E89 pressures are much higher.
Click to expand...

What do the stickers say on the E89?

I assume the use of runflats has something to do with it or just a heavier car than the E85/86.

H.
Click to expand...

Just a heavier car.
Click to expand...

The 20i e89 isn’t much different in weight to a 3.0 e85 :poke:
Rob
 
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