# Can 18" rims damage suspension on E39?



## RBB530i (Feb 3, 2006)

Greetings:

Recently a mechanic indicated that running an '02 530i on 18" rims will cause suspension damage, because the car was designed for 16"rims??? He was talking about bushings and control arms??? Maybe I'm missing something, but if you have the same diameter wheel, (16" with tires or 18" with rubber bands  isn't the suspension un-affected? Specifically, the stock rims were replaced by M-Parallel's. 

Thanks for any insight!


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## Close Encounter (Apr 28, 2006)

Most ridiculous thing I've ever heard. I think you need a new mechanic.


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## FJ540 (Jan 1, 2007)

Added weight could potentially cause wear rates to increase (bearings, ball joints, bushings), and braking performance to decrease, but the forces encountered on the road are well in excess of the added weight possible by going to larger wheels.

Nothing will outright break because of the larger wheels. Incorrect offsets will cause added stresses on the components, but that'd take stuff sticking out of your fenders by a few inches to get serious enough leverage to become problematic. Keep in mind, all automotive critical components are engineered with a "safety factor" built into the design. Usually 3+ times the highest probable load and shock.

I agree that your mechanic is a quack.


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## fobos (Oct 6, 2008)

Sorry for interrupting you guys, i just randomly found this topic on google while i was looking for something else...

Anyways, yes, 18" rims CAN damage suspension on e39. If it doesn't have a V8 engine they can damage it even more, because the suspension is weaker on R6 models (520,523,525,528,530).

I am talking from my own experience because I live in a country where roads are not as good as they are in USA. There too many wholes and when you ride on 18's you defenetly get more damage to suspension. 

Still if I would live in USA I would install 20" rims and would lower the ride by couple of inches.


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## [email protected] (Jun 10, 2003)

fobos said:


> Sorry for interrupting you guys, i just randomly found this topic on google while i was looking for something else...
> 
> Anyways, yes, 18" rims CAN damage suspension on e39. If it doesn't have a V8 engine they can damage it even more, because the suspension is weaker on R6 models (520,523,525,528,530).
> 
> ...


Stating that 18" wheels can damage your suspenion is incorrect, regardless of your personal experience.

I could find you several tires in 235/45R17 that would have a harsher ride than a touring all season tire in 245/40R18.


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## Tufast (Oct 16, 2008)

FJ540 said:


> Added weight could potentially cause wear rates to increase (bearings, ball joints, bushings), and braking performance to decrease, but the forces encountered on the road are well in excess of the added weight possible by going to larger wheels.
> 
> Nothing will outright break because of the larger wheels. Incorrect offsets will cause added stresses on the components, but that'd take stuff sticking out of your fenders by a few inches to get serious enough leverage to become problematic. Keep in mind, all automotive critical components are engineered with a "safety factor" built into the design. Usually 3+ times the highest probable load and shock.
> 
> I agree that your mechanic is a quack.


Ditto, there is very slim chance that 18"s will damage your components, although they may cause more wear quicker, but just remember that you will have to go to a lower profile tire in order to compensate for the additional diameter of the larger wheel.


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