LexDiamonds

Tried searching.. couldnt find the info I wanted..

So I am upgrading from stock 17s to 18 AMGs 7.5 front and 8.5 rear.

I understand the direct match for these is 225/40 front and either 255/265 35 rear.

Can you bump the sidewall up one notch to help fill out the wheelwell?

AKA 225/45 and 265/40?

I know this will mess with the gearing ratio and speedometer to a small degree. May also be a clearance issue?

My car has stock suspension and as much as I would like to lower it, that wont happen with the speedbumps I am forced to drive over each and everyday at work.

I guess I want my cake and eat it too.. New tires/rims are a big investment and I want to get the best size possible 1st time out of the gate.

Open to any feedback from the hivemind here.

Mka77

In order for everything to be within spec and work properly, tire sizes should never be greater than 3% difference from OEM.

Klinh

Yes. If you go with 265 in the rear then you should go with 235 in the front too so you don't change the ratio too much. Or you can go with 225 front and 255 rear.

Glyn M Ruck

Just keep rolling circumference of front to rear tyres within 2% of one another or the ESP will play up. The speedo can be recalibrated with Star if it worries you.

Mka77

PM sent

LexDiamonds

OK, the million dollar question-

Will 235/40s and 265/35s clear the stock suspension?

Glyn M Ruck

235 will clear the front. 245 won't. 265 will clear the suspension on the back. Might have the odd rub loaded in the arch.

Mka77

A 265 is a bit stretched on a 8.5" but will work.