Tire wear question Options

[john914somers]

I have an older street car that the stock camber settings are rather negative and are wearing out the inside of my tires prematurely. The tires warranty is for 24,000 miles but I seem to be getting only about 8000 miles out of them. There is lots of tread left over the whole tire except for the very inside edge of the tires are wearing to the threads. The camber settings are correct and the dealer says that this tread wear is "normal". The front and rears are a different width and the tires are directional making rotation not an option, and the tire company says that they are no longer going to honor the warranty. Sooo I was thinking that if I slightly over inflate my tires I may get more miles out of them. What do you guys think??? Thanks a ton!

[Woody]

Has the car been aligned? 8,000 miles per set is quite a bit excessive. Toe out can also cause what your seeing.

[ChrisFoley]

If you drove harder around corners the tires might last longer. (IMG:style_emoticons/default/laugh.gif)

Seriously though, how about having the car aligned with half a degree less camber in spite of the dealer's recommendations?

[balljoint]

Do the tires have a side that has to be out? Can you rotate them by swapping tires between left and right rims?

[brant]

You need a new alignment shop. Check for worn out front end components. Check you tie rod ends for looseness. Your shop is wrong

[ThePaintedMan]

(IMG:style_emoticons/default/agree.gif)

First thing to do is check for component wear, namely tie rod ends. But if that's all hunkey dory, what you're talking about is much more likely to be a toe issue, or a combination of toe and camber. I just went through the same thing on my Mustang. Brand new set of tires, but the stupid alignment guy had the wheels toed out about 1/16th too much on both sides.

[Woody]

Make sure you have some rear camber shims on hand. Likely an alignment shop wont unless they regularly align 914s. Get a printout and share it with us.
Factory specs for a 914 at factory ride height are
0 degrees front camber
+.1 degrees toe per wheel up front
-.3 camber rear
0 toe rear.

[ChrisFoley]

(IMG:style_emoticons/default/idea.gif)
I don't think he's talking about a 914.
This should really be in the garage with OT in the heading.

[john914somers]

So sorry guys, I guess I should have been more clear. It's a 2008 Mercedes E-63 and the fronts are wearing just fine. The rears however according to the dealer have this type of wear as a "normal" parameter. The car comes with pretty expensive soft and stickys and the suspension components appear OK as is confirmed by the dealer. I merely value your guys opinions as an above average auto-IQ group of guys and was just wondering what the teener nation thinks about a slight over-inflation of the tires to reduce the tread wear on the inside edge??? Sorry for the confusion.

[r_towle]

Get the specs for the rear alignment from the factory manual.
Go to sears and have them check it and give you a printout.

Something may indeed be wrong, you need to check.

Rich

[Woody]

I respectfully disagree Rich. I wouldn't let the monkeys at sears touch my lawnmower much less a Mercedes. Good chance they've never even touched one before. Have the dealership or a reputable Mercedes specialist align it again and get a print out. Maybe request less camber in the rear because of your tire wear issues. That's a heavy car with a decent amount of power on soft rubber. If I had to guess it probably calls for a degree and a half negative camber as a factory setting in the rear. It is going to eat up tires but you should be able to get them to wear evenly. In the Porsche world it is not uncommon to see rear tires wear out in 10,000 miles or so if you're an aggressive driver. Those same tires can last 25,000 miles if driven gently with a good alignment.

[ThePaintedMan]

Don't those things have an adjustable or automatic air suspension in the rear? (IMG:style_emoticons/default/idea.gif)

[r_towle]

I respectfully disagree Rich. I wouldn't let the monkeys at sears touch my lawnmower much less a Mercedes. Good chance they've never even touched one before. Have the dealership or a reputable Mercedes specialist align it again and get a print out. Maybe request less camber in the rear because of your tire wear issues. That's a heavy car with a decent amount of power on soft rubber. If I had to guess it probably calls for a degree and a half negative camber as a factory setting in the rear. It is going to eat up tires but you should be able to get them to wear evenly. In the Porsche world it is not uncommon to see rear tires wear out in 10,000 miles or so if you're an aggressive driver. Those same tires can last 25,000 miles if driven gently with a good alignment.

Just suggesting he get the numbers checked...nothing more.

[Woody]

No worries at all. If I remember tomorrow I'll see if I can pull the factory specs. Kinda curious myself.

[john914somers]

Sooo the dealer told me that the factory specs are .75-1.5 degrees of negative camber. Seems like a big margin of error if you ask me but that was from a service writer that maybe didn't want to put the effort into it. He of course suggested to bring it in right away and have it checked out. Anyway I'm thinking that if I'm on the more negative side of the acceptable specs than perhaps by adjusting the camber to -.75 maybe my tire wear will be more uniform. If I'm already at -.75 then maybe by going outside the factory specs by .5 to -.25 maybe that will help. What do you guys think?The service writer told me that if I change the rear camber settings then the fronts will then be off??? Maybe I just have to accept crapy tire wear?

[ChrisFoley]

Changing the rears will not affect front tire wear.

[Woody]

I would ask them to set the minimum amount of camber while still in spec front and rear. Its really not too much to ask for. -.75 in the rear should be fine. Also bring the car in with a full tank of gas.

[ThePaintedMan]

It's a Mercedes. You shouldn't have to "put up" with anything, especially tire wear. Something isn't right. Too much camber, and possibly toe out (if the insides of the tires are wearing). You need to have them check both and get it right. You are the paying customer.

[r_towle]

For 50 bucks you can go to sears and have them tell you how the car is setup, and do not have them change anything, just printout the numbers.

Then go to the dealer with those numbers in hand and have them do what you want.