mareish

I have a 2016 C300 4matic, not the sport model, though my car did come with the upgrade of 18" wheels. I have 30k miles on my OEM tires, which are Continental ProContact GX SSR, 18" run-flats. The front tires need to be replaced since they are at 5/32. The rear tires are at 7/32.

Performance-wise, the tires have been fine. I've gotten good wear, and I drive on Chicago-area rough roads in all kinds of weather. Of course, I preferred my previous car's Nokians non-run-flats, but those cost a great deal more. I also enjoy the peace of mind of the run-flats. So now, the dealership is telling me I can replace just the front tires, which are at 5/32, and leave the rear tires as is since they are at 7/32.

I would be replacing the tires with the same Contis. I would like to save money and just replace the front, but am concerned that the 4Matic might detect a significant difference in front new tires vs. the older rear tires. Or would it?

Another consideration is that I plan to sell the car around next October, i.e. 8 or 9 months from now. The dealership is kinda lame in general, and re the tires they are not giving me any advice about my concern about the 4Matic aspect of having 2 new tires and 2 original tires on the car. So, looking for advice on whether I should replace all 4, or just the fronts. Thanks.

mareish

Anybody? So many experts on this forum, please help me decide.

xMB007x

I'm guessing they are not staggered since you got 30k miles out of them? I have the 18 sport wheels staggered and I just replaced the fronts this fall at 16k miles. I'm returning the car soon so I put a set of used but practically new oem original tires on. Came out to like $210 for the two from ebay instead of $240 each & had my mechanic put them on. If I were you I'd just replace them all with a good used set since you are getting rid of the car. Changing just the fronts won't hurt anything but you don't want to be in the same situation with the rears when you plan to sell it in the fall. Just some food for thought...

mareish

Since I only received 1 response (really, no one else has some tires require replacement sooner than others on their car?), I asked a friend who has a hobby of restoring old muscle cars. Obviously very different from MB 2016 C300, but he's been doing it for 30 years, and does every millimeter of the cars himself, no contracting out any work, so he must know something. He advised that I'd be fine just to replace the 2 fronts, especially since I plan to sell the car in the autumn. I am posting this for anyone else who might have this same question.

xMB007x - thanks so much for your reply. I didn't want to buy used tires, because I wouldn't be confident about my knowledge on which are good ones, so that the savings didn't seem worth the risk for me.

larrypmyers

Your will be fine replacing just the front tires. Keep in mind at 5/32 there is still some mileage remaining.

The 4Matic will not be affected.

Chris Jungmann

Different wear (tire diameter size) on front and rear axles is not an issue on open center differential platforms like 4matic.

However, on Subaru it is definitely an issue as most awd Subie models don’t have an open center differential.

Source: got one of each and checked manual