threeMBs

Increasing diameter over stock for MLs is a non-issue. They can take 2", at least. The issue is what kind of tire one uses (not the size so much) and if mounted on correct size wheel. One buys ML, I suppose, cause its the safest SUV out there. Why compromise by installing inferior (to say the least) tires. Tires are the only thing touching the ground. I want the best tires to provide the best traction in all situations (especially since wheels' construction is questionable as well). But its just me. As long as you're happy that's all that counts. I'm not really questioning your choice, I just wanted to know as many detail of what you've got since I was thinking of the same route, but putting 5K lbs SUV with incredible speeds capabilities of ML550 on inferior product is too risky for me.

Nanook

There is very little room to go over stock 29.x inch diameter at least on front of a ML63 for risk of rubbing especially when turning...the stock size is very very close already

Kenn1926

I had the same issue with the rear sub. I noticed the first day I had my truck. They fixed it a few days later when I brought it in to have the remote start installed. They said something was loose from the factory, I haven't had a problem since...

threeMBs

Well ML63 is lower and uses much wider tires (295 vs. 265/255) than ML550 and ML350. What I do know is that both ML350 and ML550 can accept GL sized diameter tires (30") with room left for more.

Nanook

Possibly so but I'm referring to the clearance at the front and back of the wheel/tire to fender liner..I can barely get a finger in there..possibly because I lowered it...dunno

threeMBs

You answered your own "question". On stock (non-lowered) ML350/550 (not 63) there's room for as much as 31" diameter tires.