dmauch

I just bought a 2012 E350 Luxury sport and the current owner just had to replace one of the rear tires because there were a couple nails that the tire dealer said could not be repaired. So he had a new tire the same size and brand as the other tires installed. The existing tires have 60 percent of their tread left and my question is will it be a problem having one tire with a 100 % tire tread and the other tire with 60% cause any problems with the 4 matic becuase the new tires will have a slightly larger diameter than the 60% tire . Both on the rear.
TIA
Dan

KEY08

No.

atraudes

No kidding? I would have thought that'd be too big of a difference. I know some tire installation places will shave down the new tire to match the old ones. Any tire place worth it's salt should be able to measure and advise, though.

pierrejoliat

I had the same situation, one tire that was not repairable, out of concern for the 4matic, I did replace both back tires, leaving the 60% tread tires on the front. I believe the 60%-100% ratio falls within the 4% variance allowed by Mercedes for 4 magic.Others may feel differently, but I did the math and felt comfortable with the results.

kajtek1

Per forum members experience 3-4% difference in rpm between the wheels is just fine, when I drove on compact spare on couple of occasions and regardless it being much smaller, no lights.
You can calculate % of difference in the way like 40% of thread = 4mm, . Divide it wheel radius and you have your number.
But theory doesn't work well when it comes to tires.
Tires are manufactured with very loose tolerances and I have been catching tires from the same manufacturer, same nominal size, yet coming from different mold they had 5% difference in rpm straight from the factory.
So final test is on the road. Usually first thing to indicate problem is CC. Try if it holds at 60mph. If it does - you are good.