Anyone Running Larger Tires On OEM wheels
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Joined: Sep 2023
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2023 E63S AMG - Grey Magno
And the reason for my question is, I need new front tires and am playing around with the online calculators.
WIth Front 285/35 the Front/Rear ratios are:
295 is 3% smaller
305 is 2.3% smaller
315 is 1.7" smaller which gets back to stockish F/R ratio of 1.7%
So the "perfect" dia would be Front 285/35 and Rear 315/30
Bonus: Ditch the spacers
WIth Front 285/35 the Front/Rear ratios are:
295 is 3% smaller
305 is 2.3% smaller
315 is 1.7" smaller which gets back to stockish F/R ratio of 1.7%
So the "perfect" dia would be Front 285/35 and Rear 315/30
Bonus: Ditch the spacers
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Joined: Mar 2011
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From: Canada
2023 E63S Wagon
I do not believe there will be any issues. However, I could not run that because of my 10mm spacer in the rear. I am at the limits of what looks good and does not stick out with the stock wheel/tire and a 10mm spacer in the rear.
If I do go with larger tires in the rear in the future, I will get rid of my spacers.
Now in the front, you can go wider than 275/35/20 with no issues. I have that plus a 15mm spacer and its still clears no problem. I could go 20mm spacer to be honest.
On an unrelated note: I have detected a stability issue with my 275/35/20 plus 15mm spacer. I ordered 10mm spacers and waiting to see whether it helps.
The stability problems only happen under WOT as the speed builds. The car is fine as long as you are going very very straight. If you turn a slight bit over 40-50mph under WOT, it wants to swing like crazy to one side of the other. Seems very unstable and squirly. I am thinking it might be airflow issues since a larger chuck of tire is exposed to the wind forming around the front bumper with those spacers. It only got this way after I went with larger tires.
If I do go with larger tires in the rear in the future, I will get rid of my spacers.
Now in the front, you can go wider than 275/35/20 with no issues. I have that plus a 15mm spacer and its still clears no problem. I could go 20mm spacer to be honest.
On an unrelated note: I have detected a stability issue with my 275/35/20 plus 15mm spacer. I ordered 10mm spacers and waiting to see whether it helps.
The stability problems only happen under WOT as the speed builds. The car is fine as long as you are going very very straight. If you turn a slight bit over 40-50mph under WOT, it wants to swing like crazy to one side of the other. Seems very unstable and squirly. I am thinking it might be airflow issues since a larger chuck of tire is exposed to the wind forming around the front bumper with those spacers. It only got this way after I went with larger tires.
Scrub Radius. Spacers change it and make the car unstable/darty.
I also experience this with only my stock rims, 265, and 15mm spacers. WOT to go around a car I have to really pay attention and hold the wheel. The car is very skittish and wants to pull left/right quick and crazy. Very squirrely with the spacers when not going perfectly straight at WOT.
Interesting!
Last edited by I.T. Guy; Aug 2, 2025 at 07:18 PM.
MBWorld Fanatic!
Joined: Mar 2011
Posts: 2,496
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From: Canada
2023 E63S Wagon
"n the other hand, if our scrub radius was negative 15 mm then it is now positive 35 mm, meaning it has changed sign and now the moments around the kingpin axis generated by braking forces have not only increased but changed direction from what the suspension was designed to handle.The changes in the scrub radius and kingpin offset mean the forces the steering system, and the hands of the driver, need to resist have doubled or quintupled in strength and may even have reversed direction. That’s a lot more work the driver has to do and a much higher risk the wheel may be ripped from their hands. Don’t underestimate the impact this can have on the dynamics and handling of the car. These numbers are critical to the proper functioning of the suspension."
MBWorld Fanatic!
Joined: Mar 2011
Posts: 2,496
Likes: 1,574
From: Canada
2023 E63S Wagon
How come no one has tried a 10.5" rim on the front?
This could keep the centerline closer to stock solving scrub radius issue,
While maintaining the aesthetic poke everyone likes with an ET10
By my calcs a 10.5 rim with the same poke as people are running the 10 inch wheels at will only have 9mm more inset then a stock rim setup. Does anyone know how close the inset on a stock rim is to suspension and fenders and stuff and when turning? Is there a cm of room there?
Time for a lift and measuring tape.
This could keep the centerline closer to stock solving scrub radius issue,
While maintaining the aesthetic poke everyone likes with an ET10
By my calcs a 10.5 rim with the same poke as people are running the 10 inch wheels at will only have 9mm more inset then a stock rim setup. Does anyone know how close the inset on a stock rim is to suspension and fenders and stuff and when turning? Is there a cm of room there?
Time for a lift and measuring tape.
Last edited by I.T. Guy; Aug 3, 2025 at 09:00 PM.
