Hi,
Can anyone tell me what my wheel offset is.
Thanks.
Rafiqi.

Here is a site that has a calculator for wheel offsets:

http://toy4two.home.mindspring.com/offset.html

Hope it helps!

The wheel offset is marked on German wheels. Unfortunately I seldom use it so I can't tell you where.

I went to the link listed and there is a statement on the page I find interesting:

"The clearance from stut housing to the inside of the wheel will be THE SAME
The outside edge of the wheel will EXTEND an extra 26mm."

What he is doing in that statement is garbage. He is telling someone how to buy bigger wheels that will offer similar inside clearance. In the statement above he has gone from a 7in wheel to an 8in. He has used a different offset such that all the width change is placed at the outside of a rim.

If you look at the spec book there is a proper offset for every suspension design. If you buy bigger rims the the offset must stay the same or you screw the design. The quickest way to defeat the suspension designer is to change the offset

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

There are two possibilities..
My 1996 S500 Coupe came from the factory with 34mm offset wheels (16x8) on the rear and 51mm offset (16x7.5) on the front.
Some Coupes came with 51mm both front and back (16x7.5) which was the standard for the W140. From what I can figure out, the change to the staggered offset was made late in 1995 and dropped in mid 1997... so, you could have either arrangement. I'm told that MB changed the staggered arrangement because of confusion when rotating tires, etc.
The wheels are clearly marked on the back. The rear ones are marked "rear use only" if they are the 34mm ones. Also, ff you have the staggered arrangement, the back lug bolts are unique because of the lug depth... so, you can also tell by comparing a front lug bolt with a rear bolt.
If you do the math, the staggered arrangement provides almost identical track width front and back.
Hope this isn't too confusing.

__________________
KenP

1996 S500 W140 Coupe

i have a 1997 model year c140. it was manufactured in oct 1996. and sold by the m-b dealer in dec 1996.

the owner's manual identifies the light alloy rims as 71/2J x 16 H 2 with a wheel offset of 2.0 in[51 mm].

you should find that spec on page 132 of your manual.

all the best.

All OE wheels have the wheel size in the casting molds or forging dies and you can see it on the inside of the wheel. For a 300E it would read something like:

6.5J x 15 ET49

The "ET" is the offset in millimeters. Since most Mercs carry the spare tire outside face down in the spare tire well, all you have to do is lift the cover, spin off the retainer, and read the numbers.

Duke

Steve, I'm glad the M-B engineers did not consult you when designing the W124 500E, for example. Now that would sure look silly with 6.5" wide rims with 49 mm offset in those flares!

Albert,
Good information to know... perhaps the staggered offset on the Coupes was eliminated at the end of the '96 model year and did not continue into '97 at all... had one guy tell me his '97 was like mine, but maybe not.
My owners manual says the car can have either all 51mm or 51/34 staggered... showroom sales "guide" for the car says only 34/51mm. Curious, eh?
Duke2.6,
Looking at the spare may not help the original question... with the 34/51mm staggered arrangement on my Coupe, the spare is a "front" wheel (51mm)... suggesting they are all that offset, but they are not. The tool kit carries five "front wheel" lug bolts so you can mount the 51mm wheel on the rear for emergencies.
Either way, the wheels are all clearly marked during forging on the back side.

__________________
KenP

1996 S500 W140 Coupe

rafiqi, if you're satisfied that the proper wheels are mounted on the front and rear it appears that the best way to confirm the offset would be to pull one of each and check the offset number stamped on the back. It requires some work and/or time (depending if you pull the wheels yourself), but then you'll know for certain.

__________________
Fred Hoelzle

Hey Joe,

I sure MB doesn't need my help. They wouldn't be caught dead doing something as stupid as that link. If they wish tires to fill wheel wells you can believe they will respect the designers concept of where the center of the tire hits the road.

The center of the contact patch is what they are concerned with and that point doesn't change by putting wider wheels on. It only changes if you are doing it for looks and use the technique in the link to give inside clearance with tire sizes not capable with the current design suspension.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Steve,

MB has gone to more offset to clear wider wheels though. The example I gave is the 124 500E, which came with 16 x 8 ET34, an offset increase of 15mm over the standard 49. The suspension design engineers must have felt that this was acceptable for the geometry of this suspension. They also went to more offset on the later years of the W124 model run, ET 42, I think.

I do agree that this can get rediculous, as seen in a front driver (that usually has considerable negative offset) with large positive offset wheels that put the tire a few inches outside the body. Geometry is whacked with excessive bearing loads and likely drives terribly.

Personally I feel comfortable with anything within the range that the factory has done. I just mounted 17 x 7.5 ET35 rims on my 300E. That is less offset than the 500 used, everything clears well, drives nice and looks great. No regrets.

If MB changed the offset, what else did they change. If they changed the ride height the center of the contact patch moved and they would need a offset change. I suppose that MB also could be influenced by MONEY. They know there is an element of the buying public ready to screw their car with mods. They have their hand out also! Lots of good repairs and parts to supply to that group.

If you change the offset and do no changes you have guaranteed a reduced ride.

It is my firm convistion that those who need big wheels to satisfy their "look" have reduced capability to say "drives nice and looks great".

I would have to say that I am at least as opinionated about this as all the big wheelers. I just have to ask you, if you could imagine, that my opinion is based on driving you all's big wheeled rides every day as I fix them. I find that owners of cars have a very biased concept of how they ride with those big wheels.

I just have to drive them and even though I may be biased, my bias is based in technology and the seat of my pants!

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician