How Wide Can I Go?

ClevelandBeemer · 10-02-2019, 06:38 PM

Hi everyone!

I autocross have been in the persuit of more grip. I'm currently using a square set of 245/40/18 Bridgestone RE/71R's for autoX events. But at the power levels I'm running at I can use wider rubber in the back and more grip up front would not hurt either.

I'm not opposed to a staggered setup as that's what I daily drive with. What is the widest 18" wheel and tire combo I can get away with without rubbing or rolling fenders?

wdeerfield · 10-03-2019, 07:59 AM

i believe you can run an 18x9 with a 255 square.

Expert@ApexWheels · 10-08-2019, 03:22 PM

Quote:

Originally Posted by wdeerfield

i believe you can run an 18x9 with a 255 square.

Indeed, with stock suspension or lowering springs, you can run 18x9" ET30 with 255/35-18 tires all around as a direct fit with no modifications required. Certain coilover setups may need front spacers, but not likely unless the car is very low.

Wider tires can also be used, but will require front negative camber, and may need rolled rear fenders as well depending on ride height and tire brand.

F30 on H&R springs with 18x9" ET30 with 255/35-18 tires all around

--Dylan

aps · 10-08-2019, 04:03 PM

square 9.5 et35 is the limit without camber plates. but widest tire with that set up is still gonna be 255

ClevelandBeemer · 10-12-2019, 10:04 PM

That’s what I needed to know. Thank you everyone!

10-02-2019, 06:38 PM	#1
ClevelandBeemer Second Lieutenant 94 Rep 262 Posts Drives: 2013 BMW 335i M-Sport Join Date: Jul 2014 Location: Cleveland, OH iTrader: (0) Garage List 2021 BMW X5 45e [0.00] 2013 335i [0.00] 2015 BMW S1000R [0.00]	How Wide Can I Go? Hi everyone! I autocross have been in the persuit of more grip. I'm currently using a square set of 245/40/18 Bridgestone RE/71R's for autoX events. But at the power levels I'm running at I can use wider rubber in the back and more grip up front would not hurt either. I'm not opposed to a staggered setup as that's what I daily drive with. What is the widest 18" wheel and tire combo I can get away with without rubbing or rolling fenders?
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10-03-2019, 07:59 AM	#2
wdeerfield A family of bimmers 2747 Rep 7,742 Posts Drives: '18 G01 X3M40i Join Date: Jan 2012 Location: Clifton Park, NY iTrader: (0)	i believe you can run an 18x9 with a 255 square. __________________ 2018 PB/Black G01 X3M40i \| 699M \| ZDA \| ZPP \| ZPX \| Maxton front lip \| X3M vents \| 15mm Spacers \| Diamond G20 style grills
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10-08-2019, 04:03 PM	#4
aps Captain 336 Rep 963 Posts Drives: 2018 M3 ZCP Join Date: Apr 2016 Location: NC iTrader: (6)	square 9.5 et35 is the limit without camber plates. but widest tire with that set up is still gonna be 255
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10-12-2019, 10:04 PM	#5
ClevelandBeemer Second Lieutenant 94 Rep 262 Posts Drives: 2013 BMW 335i M-Sport Join Date: Jul 2014 Location: Cleveland, OH iTrader: (0) Garage List 2021 BMW X5 45e [0.00] 2013 335i [0.00] 2015 BMW S1000R [0.00]	That’s what I needed to know. Thank you everyone!
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