MBstve

Hi, does anyone know the correct offset for 2011 E350 20 inch?

planning to buy 8.5x20 offset 35 front
and
9.5x20 offset 35 rear, will that fit?

and also what tires should be used?


Thanks

Alex.currie44

There is no standard 20 inch wheel for the 2011 W212. The standards are 17 and 18. It is a choice thing.
You are going for a staggered set up which means you cannot rotate tires front to back.
The fronts as you describe them will have 13 mm more clearance than the stock 48 mm and the outer rim will be 13 mm further out.
The rears will have the same clearance as the stock 48 mm but will project outward an additional 26 mm.
You can look this stuff up on line at places like 1010Tire etc. who have offset calculators and tire comparators.
As to what tires to be used, it's your choice but you have to be cognizant of the fact that you should stay within the same circumference as the stock tires so aspect ratio is important. You can check on that at 1010Tire as well in the tire comparator.
The base 17" tire is a 245 x 17.
Be prepared for a harsher ride and get wheel insurance.

MBstve

Thanks for the reply!

My main concern now is that will the tires/wheels rub the fender?

Cause I had this problem on the C class before, I installed 19x8.5 35 offset, the wheels were rubbing the fenders a little when i hit a bump at high speeds.

Alex.currie44

That no doubt was because you did not insure that the overall circumference i.e. diameter was the same as the stock wheel/tire combos. As you go up in wheel diameter, you have to give up wall height.
I am not trying to bore you with the math but it is in fact simple so here is an example of how the factory did my 2014 SLK350:
On 17" wheels the front spec for summer is 225/45 17 and the rear 245/40 17
The aspect ratio is 45% of the width which is 225 for the front so the wall height is .45 x 225 = 101 mm or 3.97 inches so the diameter of the tire will be 2 times the wall height plus the diameter of the wheel itself. (3.97 x 2) +17 or 24.97 inches
On the rear it will be .40 x245 = 98 mm or 3.86 inches so the diameter of the tire will be (3.86 x2) + 17 or 24.72 inches. More or less a match.
On the 18 " option for my SLK the tire sizes are 235/40 18 and 255/35.
Again doing the math front .4 x235 = 94 mm or 3.7 inches and the tire diameter will be (3.7 x 2) + 18 or 25.4 and the rears 255 x.35 = 89.25 mm or 3.57 in and the diameter (3.57 x 2 + 18 = 25.14 inches
So on the same car you have two different diameter wheels but by selecting the correct aspect ratio of wall height to tread width you have a range of diameters from 24.97 to 25.40 in the front for a difference of .43 " diameter and the fenders and suspension are clearly meant to clear the bodywork. They have to clear otherwise you couldn't make sharp turns.
In the rears the difference is from 25.14 to 25.4 inches or .26 in diameter.
So turning to your 2011E with a 245/45 17 standard tires the wall height is .45 x 245 = 110 mm or 4.34 inches and the diameter is (4.34 x 2) + 17 = 25.68.
On 18s the stock size is 245/40 so again 245 x .4 = 98 or 3.86 x 2 = 7.7 +18 = 25.7.
This has to be your target tire diameter if you want to clear the fenders. Anything significantly greater and you will have the same issues as your C.
My guess is a 245/30 for the front. Doing the math 245 x.30 = 73.5 or 2.89 and (2.89 x 2) + 20 = 25.79.
For the rear, given your are going to a 9.5 inch wide wheel I am guessing 255/30 which comes out to just about 26.
Any good tire shop can guide you but you have to stay within the spec wheel and tire combos for diameter if you want to avoid clashing. That is why large wheels need low profile tires.

MBstve

Thank you very much for the reply!!!
I learned alot