cal1

I have been running Toyo T1Rs for the past few years going through two sets. i like them, but have noticed some cupping taking place on the inside edge of the front tires. Both front tires have the same wear pattern. MB did an alignment before I put the first set of tires on and said all front end components are in good shape. I got the same pattern on the first set as the second. The tire guys say it is the camber of the MB.

I just had a new set put on and noticed the tire guys set the pressure at 32. It is also what I kept the tire pressure at on the old sets thinking they knew what they were doing. This is 3 pounds below what MB recommends as a minimum for the SL. I wonder if this is why I am having the wear issue. Could it be the tire store has no idea how heavy of a pig the SL is and thought 32 was a good pressure? I like the way the car handles and feels better at 35 anyway.

Rook3300

I do know that SL's will wear out the inside edge of their tires much more quickly due to the camber in the suspension setup. It's there for better handling at speed when the car tends to squat down more.

With my old set of Michelin Pilot Sport+ A/S, I tended to run higher pressures for better fuel economy and freeway ride. This wore out the middle of the tire much quicker than the edges due to the bulge in the middle. I didn't think a few pounds would make such a difference but it did. I would suggest that if you're running different pressures than MB recommends, keep a close eye on where wear is occurring. (LOL, trying saying that last sentence out loud.) You could be out of tire much sooner than you expect.

Good luck and drive fast!

-ROOK

cal1

So it sounds like there might be a "sweet spot" where wear is maximized or I guess minimized I do have another issue with my tires: the rears wear out much faster than the front. Could be my driving habits.

JBFMCAR

What do you guys think the best PSI is front and rear i run the 19in CLS wheels with PS2s at factory specs right now might add 2-3psi on top of factory specs since i do alot of highway driving.

okbarnett

Are you using stock wheels? What sizes do you have? Have you lowered the car?
Front end has a factory camber adjusting bolt you are supposed to use to adjust the camber sag out of the car. Car starts saging after a few yrs. If you get them you can straighten up the front.
Nothing is possible for the back except adjusting up the height.

jmf003

LOL. It's your right foot, Curt!

cal1

yes, stock wheels stock tire sizes: Fronts: 255/40 - 18 Rear: 285/35 -18. The car is not lowered. I only have go fast mods. She's a stocker on the outside.

Should the stealer have adjusted the camber bolt at the last alignment?

Thanks a bunch for the help.

cal1

Well what can I say... I don't think the little SL is happy if she doesn't get to smoke the tires now and again.

okbarnett

My experience is to keep the tires inflated to the upper limits. It keeps the ride firmer, makes the tire more expanded and more squared on the tread. And allows the geometry of the suspension to be more square and upright rather than slouched. If you have this pressure when you align it, then it will still have the same alignment values as your driving at that pressures. This might be all very small amounts, but it is still a factor. Look at your tires and get the Max inflated pressure, maybe 44lbs.. etc. I keep about 40lbs in mine then watch the TPMS reading on long drives or hot. It might reach 42, 43 44 lbs. Then Its good. Its near its max for the tire.
Now the alignment, Your car has a round shaft camber bolt from the factory. It gets older and sags. They make a replacement bolt for the front that has grooves that will compensate for that. you have to buy them and replace them But as usual, you cant trust every man that works on the car to do the right thing. Youll have to ask for the dealer to read the specs and see if they need to be inproved with the bolts. OR just say you want it done because of the wear.
About $75 for the bolts.. There is none for the rear. THERE NEEDS TO BE> but there isnt.
You can buy the adjustable arms from renntech etc for about $5000.
Or just keep buying tires for the back.

MRAMG1

Although mine is an S600 here is my set up which is what I also used in the C32.

Local

F-36 R-28

Long distance

F-38 R-38

Dragin

F-40 R-22

Road racing

F-40 R-34

Note these are all starting points only, adjust for individual driving style and fun