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[DeviousG]

Hi

Is it possible on my 2008 E90 to change from 18" to 19"

Currently have

Front - 225/40/RF18
Rear - 255/35/ZR18


I want to change to the below on 442m style alloy which will come with the below tyres already fitted

Front 225/40/RF19
Rear 255/35/ZRF19

Many thanks

[rbryantaz]

Originally Posted by DeviousG

Hi

Is it possible on my 2008 E90 to change from 18" to 19"

Currently have

Front - 225/40/RF18
Rear - 255/35/ZR18


I want to change to the below on 442m style alloy

Front 225/40/RF19
Rear 255/35/ZRF19

Many thanks

The rule of thumb is that you want to drop the aspect ratio by 5 when you increase the wheel size by 1".

To have the original size you would want 225/35/19 and 255/30/19.

I personally increased my tire size to 235/35/19 and 275/30/19 which is very slightly larger than stock and a closer match in diameter front to rear than the 225/255 would have been.

It is possible to go up a bit in size but I would increase the width and decrease the aspect ratio.

There are a ton of threads on how big wide you can go with specific offsets for the e90. The pre-LCI rears have a bit more room than the LCI cars IIRC.

This page has some good info for the e90: https://support.apexraceparts.com/hc...-Fitment-Guide

-Rich

[DeviousG]

Originally Posted by rbryantaz

The rule of thumb is that you want to drop the aspect ratio by 5 when you increase the wheel size by 1".

To have the original size you would want 225/35/19 and 255/30/19.

I personally increased my tire size to 235/35/19 and 275/30/19 which is very slightly larger than stock and a closer match in diameter front to rear than the 225/255 would have been.

It is possible to go up a bit in size but I would increase the width and decrease the aspect ratio.

There are a ton of threads on how big wide you can go with specific offsets for the e90. The pre-LCI rears have a bit more room than the LCI cars IIRC.

This page has some good info for the e90: https://support.apexraceparts.com/hc...-Fitment-Guide

-Rich

Hey Rich

Thanks for your input,

Basically I have the opportunity to buy these 442m alloys with the tyres, just wanted to know if I could put them straight on my E90 without having to buy new tyres also, would there be any major issues if I didn't reduce tyre ratio by 5

Many thanks

[rbryantaz]

Originally Posted by DeviousG

Hey Rich

Thanks for your input,

Basically I have the opportunity to buy these 442m alloys with the tyres, just wanted to know if I could put them straight on my E90 without having to buy new tyres also, would there be any major issues if I didn't reduce tyre ratio by 5

Many thanks

They should fit if you haven't lowered the car from stock.

They will only be 4% bigger. BMW tends to be conservative with the speedo where it reads slower than actual speed with stock tire sizes. With these you will get the real speed so that is good to be aware of.

It could rub slightly on the front inner fender at full turn so that would be good to check.

The 442m rear has a a 47mm offset so it moves the tire inward by 8mm compared to e90 wheels and is only 8.5" wide in the rear so you actually probably can't go much wider.

-Rich