I have 18" rims and 235-40-18 Pirelli's on my 560SEL. At first I got a shimmy at about 35-40 and at over 80mph. I had all four wheels balanced again (they had been already balanced at installation). The low speed shimmy disappeared, but the high speed shimmy remained. I switched wheels and tires with my 560SL thinking it might be the rims and or tires. The 560SL drove smoothly with the 18" wheels and the 560SL drove smoothly with the 15" wheels from the SL. Now, I have bearing noise from the front end of my SL that I didn't have before.

My mechanic tells me that the larger wheels and lower profile tires change the camber and may change the stress points of my bearings and that any front end wear on the 560SEL may have accentuated the harshness of the lower profile tires and larger rims.

At this point, I may sell my 18" wheels and tires and stick with stock sized rims on both cars. I like the way both cars ride with stock rims and tires. I see many Benzes with oversized rims and low profile tires. They must ride somewhat smoothly. Does anybody with oversized rims have this problem?

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1991 560SEL (254K miles)
1980 Lincoln Mark VI - Givenchy
1979 Lincoln Mark V Collector's Series
1979 Lincoln Town Car Collector's Series
1979 Ford "Effie" Pickup (in gradual transformation to a show/street truck)
1969 Lincoln Mark III (waiting for "Overhaulin" to call)
1989 Lincoln Towncar
2001 Lexus GS300 (spousal unit's daily driver)

I have that same problems but with stock tires, i thought it was my driveshaft, shake at 30 then again over 80.

my car is a 500 SEL. If the SL doesnt have any problems with the larger tires might have to look elsewhere.


I didnt think you could change the camber of your car with tires... Thats done by changing the alignment. But lower profile tires do have less cushioning ability.

food for thought.

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1984 Euro 300SDC, (4spd standard)
1986 Toyota Landcruiser Diesel HJ60 5spd X2

Gone but not forgotten (some sold, some stripped)
1983 300 SD, 1985 300 SD, 1983 240D, 1986 300 SDL, 1985 300 SDL, 1983 300 D, 1984 300 D, 1985 300SD, 1987 300 SDL, 1983 300 SD, 1985 300 TD Euro, 1983 380SEC, 1990 300 D, 1987 300D, 1982 300D, 1982 300D, 1994 E420, 1987 300 TD, 1987 300 D, 1984 300 D

if the wheel center is further out from the pivot point of the suspension it is the same as lengthening the board on a teetertoter. so it imposes more force which compresses the spring less and would slightly increase bearing wear.

so if the offset of the new wheels puts the center of the tire further out yes it would make more negative camber.

a real low profile tire like that will definately make more harshness in ride. it also makes steering input more sensitive.

i drove a magnum with 20s that was very squirelly to drive imho.

my mag with the 18s is not.

good luck

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

The obvious comment is that the suspension of the 560SEL was not designed for 18" low profile tires. The some of the newer MB's were designed for lower profile tires. Not really surprising there are issues with low profiles on older cars.

Steve