Adi-Benz

Will they fit
Will it stick out too far?
Will my spedo need recalib?

18x8
18x9 I guess? maybe 9.5? unclear :S

245/40/R18
275/35/R18
and/or
225/40/R18
265/35/R18

I guess I'm leaning towards the 265's.

Thank you for those who help in advance.

MB Marko

whats the offset? is the main question.

no need for speed recalibration, they do that if you put on a major difference in sizing.

225/40/R18 will fit I'm running those on the front i can't remember what my rears are but I'm pretty sure there 265/35/R18 i can confirm tomorrow.

check the manual it says what the optimal tire size is for 17's and 18's

also I'm running
18x8.5
18x9.5
summer for my summer wheels

Adi-Benz

+40 for both I think? Man this website is lacking details.

pm sent

main goal of course is they dont stick out of fenders

mykthex

If you go with 8.5 for the front and 9.5 for the rear, don't go with more than ET45 for the offset or they will stick out of the fenders.

My next set of wheels will be:

Front: 8.5" ET45 with 225/40/R18
Rear: 9.5" ET45 with 255/35/R18

pozi240

"Fitting" isn't really the major issue to ask yourself here, but, the rolling diameter difference from front to back since your car is a 4matic.
The factory 18" staggered setup for a 4matic (have it on my car OEM) is 225/40/18 front, 255/35/18 rear. With this setup, the difference front/rear is only .4% (804 revs per mile vs 806 revs/mile).
Your proposed setup of 245/4018 fr/ 275/35/18 rr is good as it also only .4% off (785 revs/mile vs 789 revs/mile), however, the tires are taller, so, your speedo will be off. The second setup (225/40/18 fr/ 265/35/18 rr) isn't too bad either but it is .8% difference (804 revs/mile vs 797 revs/mile). This setup would be better for speedo and front fender clearance.
I personally would still stick with the OEM sizes given the sensitivity of the M-B transfer case in these cars. The information I was given by several Mercedes sources, dealer techs and a trusted independent M-B tech was "as long as the rolling diameter front to back is within 1% of each other, there is no excess wear in the transfer case".... of course, YMMV.
Cheers,

Adi-Benz

Thanks for the info. There's a lot of questions I couldn't cover so thanks for getting a bit more into it.

Plan on going 265's instead of 275, 75's are too big. 255's aren't an option with the wheel choice so I suppose they won't work :S

This transfer case stuff is such a joke you would think a big german company like Mercedes would know how to make something solid by now. What can you expect I guess. So .4% and .8% being said then either will work because they are <1%? Which would you guys suggest be the better option? I didn't think the 265's would be so far off at .8%

pozi240

Both proposed setups are under 1% difference, so, you should be fine (according to M-B). The OEM setup is only .4%, but .8% is still fine.

teja1936

I am running the following: Front 8" X 18" with ET 45 with Continental ‘ContiSport3’ 235/40/18 (F) and Rear 9" X 18" with ET 54 with Continental ‘ContiSport3’ 265/35/18 (R) with no 'rubbing' issues whatsoever

Adi-Benz

might as well blow the transfer case the sooner the better 215-295


weak sarcasm to myself

Adi-Benz

How much will the spedos be off on both cases?

pozi240

Not a 100% sure, but, here is a site I use to get percentages when running staggered tires.
https://tiresize.com/calculator/