CLS ET28 wheel to replace ET48 2010 E550 4matic wheel? - PeachParts Mercedes-Benz Forum

Steve M · #1 11-20-2013, 10:48 AM

I want to put snow tires on my E550 4matic, which has the common 18x8.5 AMG wheels all around (A212 401 2302). 245 40 R18 tires.

There's a set of snow tires (245 40 R18) on 18x8.5 R18 CLS rims (A219 401 2302) that has a very different offset (ET28, rather than the AMG's ET48). I believe that no MB wheels for the E550 have offsets anywhere near as small as ET28.

I thought the smaller offset wheels would stick out further on the car, but the dealer parts guy told me they would be in closer, possibly hitting the calipers. I don't understand this subject very well.

Is it ok to use the ET28 wheel on this car, in place of the factory ET48's, and if not, what problems would they be likely to cause?

Ferdman · #2 11-21-2013, 06:28 AM

Steve, I agree with the MB dealer Parts Department rep. Your best bet is to purchase the correct size wheels (new or used) then mount snow tires.

Luke@tirerack · #3 11-21-2013, 01:17 PM

the lower the offset the further outward the wheels

The offset of a wheel is the distance from its hub mounting surface to the centerline of the wheel. The offset can be one of three types (measured in millimeters).*

Zero Offset

The hub mounting surface is even with the centerline of the wheel.

Positive

The hub mounting surface is toward the front or wheel side of the wheel. Positive offset wheels are generally found on front wheel drive cars and newer rear drive cars.

Negative

The hub mounting surface is toward the back or brake side of the wheels centerline. "Deep dish" wheels are typically a negative offset.

If the offset of the wheel is not correct for the car, the handling can be adversely affected. When the width of the wheel changes, the offset also changes numerically. If the offset were to stay the same while you added width, the additional width would be split evenly bet

ween the inside and outside. For most cars, this won't work correctly.

Steve M · #4 11-21-2013, 03:37 PM

Well, I think Luke's drawing and explanation both support my initial belief that the ET28 wheel would be further outward than the current ET48 wheel. Since the wheels are the same width, that means that everything, including the centerline, is about 3/4 inch outward. Since MB has dozens of wheels for W212's, from 16 inch to 19 inch, and none of them have ET's lower than the mid 30's, I don't think I have any business pushing beyond their limits, even if the wheels would fit.

My preference is to find wheels that fit without using hub rings, spacers, special lugbolts, etc. Only a few OE w212 wheels fit the E550 4matic. I would prefer to go with 17 inch rims, if for no other reason than to keep the cost of the tires themselves down (though I also prefer the higher profile during pothole season).

The official Mercedes winter package for this car, at mbwheelandtire.com, is a 17 inch, ET48 package. (It's a wheel that is sold in Africa and elsewhere, Gulshorn A212-4301-1902) My parts guy said that it will fit all W212's, other than AMG, without qualification.

I think I will get a wheel that size - that way 5 years from now when I'm selling them on CL, I can guarantee people that they will fit all non-AMG W212's.

Ferdman · #5 11-22-2013, 07:19 AM

Steve, Luke's diagram shows the opposite of my understanding of offset. Presuming Luke's diagram is correct (any one would expect it to be since he works for Tire Rack) the lower ET wheel would likely cause rubbing problems with the fenders and potential handling problems. You are making a wise decision to avoid spacers, special lug bolts, etc. No doubt you appreciate that it will be fairly expensive to buy winter wheels and snow tires; however, I think it's smarter to choose that option instead of mounting/dismounting snow tires on your existing wheels every winter. If nothing else it's definitely more convenient. That's why most owners opt for all-weather tires all year.