Jay70

Hello guys.


i have CLS550 2013, and I’m thinking to have 245/40/19 in front. My wheel size is 19. Side note the reason I want to have this size because the rough roads and potholes everywhere. Bent wheels every couple months even with a careful driving, also I want to mention I don’t care at all about how this will effect the speed, performance etc. is this size will fit in front without any rubbing or any issue?

Thank you.

Tbbt CLS

Go to https://tiresize.com/comparison/

It looks like the taller sidewall tire is 1" taller. While I don't have any personal knowledge that they will fit, we have tons of room around our tires. I'm guessing you would be OK. If you have 4Matic, you would also need to match the tire circumference in the rears too (I think I would do that anyway). If you look at people with lowered cars, they don't seem to have a problem. I'm sure you would be OK. On my previous car, a 2010 Cadillac CTS Wagon, I did exactly what you want to do for the same reasons. Marv

MBmemphis

I already sent a size bigger in the back and now I’m simply waiting for front to wear out to do the same

Roop94

Think it is a myth that you have to have the same profile or same sized tires front and back if the vehicle is AWD/4Matic, whichever term is used. Mine is RWD and it comes with staggered set-up. 255/35/19 285/30/19. I've looked around online for the set-up of a 4Matic, but it had 18" wheels with 245/40/18 285/35/18. It comes stock at those numbers. You can do staggered or whatever set-up you want, but just make sure the size difference shouldn't be out of this world.

If you want to go one number up on tire prof to 40, it shouldn't give you any clearance issue. You're simply going up from 35 to 40. If you are driving at stock suspension height, you are good to go. I have mine lowered approx 1.5 inches all around, no clearance issues at all, stock wheels/tires. Just ordered 20inch wheels yesterday...going with the set-up 265/35/20 (or 275 if it allows) and 295/30/20 (or 305 if it allows). Shouldn't have clearance issues, but may have to roll fenders a bit. it's 20x10 and 20x10.5.

Tbbt CLS

I'm new to Mercedes, however, my past experience with a Cadillac CTS, confirmed that you had to stay within 4% difference in revolutions per mile. Doing otherwise would cause differential problems. Because the Mercedes 4Matic system is AWD all the time, I would think there is some % you need to stay within. Maybe the OP should contact their dealer.

Roop94

That % is I'm unsure about. Never owned a AWD sedan/coupe. Just trying to understand the concept, how does that % work? And how would it cause issues with the diff? And how do you measure that %?
I was just saying that in general and what I thought it was just a myth? lol
Please, do explain

Tbbt CLS

If your rear tires are turning at too different revolutions per mile than the front, it will destroy the center differential. I'm sure MB has some % difference they require. Go over that, have differential problems and your warranty for the differential is voided. These differentials are electronically controlled and the clutch plates would wear out faster than normal. If someone else has better knowledge, speak up now.

harryTAM

Do you know what is the offset of wheel did you order for the front and rear? A lot of other member keep saying something about the clearance problem in the front when they go something bigger but other not. I think the offset play a very important role. Could you share with us about the clearance after you put it on too?

threeMBs

265/35-20 will definitely not fit upfront (255/35-20, with a perfect offset wheel, is the tallest one can fit upfront). 295/30-20 is an extreme boarder line option in the back (305/30-20 will not fit for sure).

Roop94

Well, that didn't work out lol I told the shop do what's necessary, but would be great if they can fit wider. They listened. So Ferrada called them back and Ferrada themselves are downsizing the wheels to 20x9 20x10.5 lol they won't even do 20x9.5 in front So it will be 255/30 in front. they will try to see if 265 fits, if doesn't, we will go with 255. since mine is lowered and I'm open to roll the fenders, we will see what we fit in there.
So the final product will be available by Monday. I will make a new thread on it and post pics.
I just wanted to do as wide as possible lol but whatever works...i'll go by that


@Tbbt CLS Hmm, now I am kind of understanding that concept. Though I don't fully understand it, but I can kind of picture it in my head, you know what I mean? lol It makes sense a bit. So what is the 4%...how do you calculate the %? Does the front tires specs need to be within 4% than the specs of the rear?

Tbbt CLS

Roop94,

Yes, the front and rear tires need to be within 4% of each other when you compare revolutions per mile. Use the tire size link I provided (tiresize.com/comparisons) to compare them. Put the tire sizes you want in the compare chart, take the revolutions per mile of the largest one and multiply it by .04. If the front tire is smaller than the rear minus the .04 you could have a problem. I hope this helps. If you don't have 4Matic, it's not critical, but you don't want them to look goofy. Marv