Replacing one tire on axle
I checked the tire tread myself across the 4 main grooves and these are the measurements I got for each tire. Each number is /32 and starts from the outer grooves and goes in on the four main grooves.
RL: 8 8 9 9 8
RR: 6 7 8 8 6
I haven't noticed anything while driving, but given that our cars have the rear LSD and the 4Matic+ system, I was wondering if this is fine or if I should go back to the dealer and get a new RR tire asap. If I do need to change it but it's not urgent, I have to go back in for Service B in 30 days anyway and wondering if it's ok to keep driving the car until then. Neither the manual nor the AMG supplement say anything about this.
What do you all think?
Rolling radius depends on tire OD of course but also air pressure and tire load since it not round with weight on it as bottom is squished a bit.
Since this is so minor if anything you might possibly feel the car want to pull to one side but I doubt it.
IF worried lower pressure on the new tire a few PSI versus old tire
Called Mercedes and they arranged for a flatbed tow truck to bring the car to my dealer for a new set of PS5s. Tow truck driver said the same thing, he tows Euro sedans for the same issue all the time.
Can't really see the problem standing next to the car or looking at it from the rear. Need to bend down and look under the car closely at the inner edge of the tires.
Worn rear tire inner edge
New PS5 for comparison
finally tried my dealer/SA who is technically knowledgeable and he told me it's not a problem at all and you can replace one and 4matic will not care. i elected to replace both fronts with the same tire as on the rears (DWS06+) and keep the loose good tire for a backup. it drives great. in 5-8k miles i'll probably just swap the rears as a pair and call it a day
this is only my personal opinion but i wouldn't want mismatched tires just due to treadwear differences (though I would guess the PS4 vs PS5 is marginal) though to your original question i can't imagine it would actually cause or accelerate a mechanical issue when we are talking about like 0.25% or so rolling circumference. not sure how the LSD would affect that in your 63 models
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Called Mercedes and they arranged for a flatbed tow truck to bring the car to my dealer for a new set of PS5s. Tow truck driver said the same thing, he tows Euro sedans for the same issue all the time.
Can't really see the problem standing next to the car or looking at it from the rear. Need to bend down and look under the car closely at the inner edge of the tires.
Worn rear tire inner edge
New PS5 for comparison
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I actually got both fronts replaced last year after a nail in one tire; the same-day service advisor at the time was different to my usual guy and measured the fronts at 5 or 6/32 so I ended up changing them both.
Been hearing a lot of good things about the Pilot Sport S5s, I think those will be my next tire whenever I get the opportunity!
Often quoted reassuring “Will Carry Out a Full Front and Rear ‘4’ Wheel Alignment”.
Is now only basic Toe - directional adjustment (new car industry’s best kept secret).
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Onus has been put back on owners to fund costly, premature tire replacement !
Now a compromise of one setting. No ongoing adjustment to cater for high cambered roads with excess passenger side edge wear. Altered height through load carrying or lowering with excess inner edge wear both sides. Performance driving and excess outer edge wear. No adjustment to cater for curb knocks !
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Last edited by K-Mac; Oct 11, 2025 at 06:00 PM.













