Sl55 amg wheels , tyres, problems

[Tylerhayles1]

So where do i start basically curious

for those are a familiar and are tyre and wheel freaks, there is something known as rolling radius etc
The sl55 comes stock with
Front 255/40/18
Rear 285/35/18

some may have experienced some may have not that if you mess around with tyre ratios/profiles to much and dont keep within a certain limit you car can even go in limp mode and experience esp and transmission problems ( yes i done this with 35R on front and 40R on rear)

i always liked the idea of meatier tyres but has to be done in certain ways,

now i was going to do a suspension overhaul accumulators, valve block etc because im not to happy with my ride at the moment,
But now also looking into wheels and tyres more im concerned my set up also may be causint problems, ride quality, handling and even potentially transmission and power problems because of how the sensors relay for information.
so here goes

I have
255/40/19
275/40/19
now learning abot tyre ratios etc i have realised how ****** stupid this set up is and what it could potentially be doing to my car despite how good it looks

to think that if you car can go into limp mode with a bad set up, can a still bad set up but not as bad that it dont throw up codes, can it still be restricting your car without you knowing, my quest is could my set up actually be causing problems
Be nice to hear from experts or people who have actually dealt with this stuff

After checking ratio calculators
Im set on.

255/35/19 or 265/35/19

rear 295/30/19 or 285/30/19
Thanks

 

[AMGeed]

The recommended set up on 19's for the SL is 255x35x19 front and 285x30x19 rears

 

[Tylerhayles1]

The recommended set up on 19's for the SL is 255x35x19 front and 285x30x19 rears

Okay mate,
I may try 295/30/19 on rear? Don’t think make to much difference, still within the 2% on rolling radius

 

[Bobby Dazzler]

Okay mate,
I may try 295/30/19 on rear? Don’t think make to much difference, still within the 2% on rolling radius

Your first post suggested that you’re concerned about limp mode and error codes, or even problems which may be hidden. I would therefore still the standard sizes.

 

[Tylerhayles1]

Your first post suggested that you’re concerned about limp mode and error codes, or even problems which may be hidden. I would therefore still the standard sizes.

yeah absolutely i agree,
I know a rule of thumb is if you go 18” to 19” then drop your profile by 5mm eg 40 to35
But i mainly wanted to know if what i was saying was true or if there is any mercedes (scientists) that could actually go yep you are right it will cause problems sort of thing, or people that have been through it all

 

[John]

I know a rule of thumb is if you go 18” to 19” then drop your profile by 5mm eg 40 to35

Profile is a percentage of the width of the tyre rather than a specific measurement per se.

So the difference between 40 and 35 is 5%.

 

[Tylerhayles1]

Profile is a percentage of the width of the tyre rather than a specific measurement per se.

So the difference between 40 and 35 is 5%.

Gotcha ok, so do you personally think with all the wrong tyre set up/ profiles apart from handling it can cause other problems?

 

[Bobby Dazzler]

Gotcha ok, so do you personally think with all the wrong tyre set up/ profiles apart from handling it can cause other problems?

It can interfere with control systems which take inputs which change depending upon rolling radius, eg ESP. There’s no scientific way of determining how far out of spec you can go before encountering issues. Keeping to factory sizes is the best was to reduce the risk.

 

[Tylerhayles1]

It can interfere with control systems which take inputs which change depending upon rolling radius, eg ESP. There’s no scientific way of determining how far out of spec you can go before encountering issues. Keeping to factory sizes is the best was to reduce the risk.

yeah thats what I thought l, considering how ott the electronics are on these cars wouldn’t surprise me if it can cause traction and even shifting problems

 

[John]

Gotcha ok, so do you personally think with all the wrong tyre set up/ profiles apart from handling it can cause other problems?

You've touched on the potential problems I can think of already in your original post (and obviously the rolling radius subsequently which will knock the speedo accuracy out and you will probably scuff wheel arch liners when you turn the steering / ESP not being happy with what is going on / disabling safety features).

I've never done too much to my cars in terms of wheels and suspension apart from lowering, harder suspension (but I never went extreme like slammed) and ran CLS55K 19 AMG wheels on a W211 E55K which they were never designed to fit on but they were close.

Saying that, the cars I had in my early years weren't as sophisticated as an SL55 so you just messed up the handling or increased tyre wear etc. but nothing more.

My 55 never complained about the wheels as I still ran it with a standard suspension setup.

But put simply, to avoid potential problems, stick as close to standard as you can (e.g. post #2).

The further away you deviate, the more you are likely to hit problems - some of which may not be immediately obvious.

I've no doubt there are some who have been down the same road and know what the results are of certain setups (you'd probably need a tuning forum really with people who do extreme suspension geometry / wheels etc.).