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[mack128i]

Hey all,

Very new to car mods, and are wanting to put 18s on my 128i. I have just learned about offset and want to ensure that the offset for the custom wheels will not be anymore than the OEM ET.

Additionally, I am seeing that 255/35/18 should provide a squared fit for the set up, not wanting to run any camber, just a square fit with no rubbing, or at least minimal on any hard bumps etc.

Wanting to run wider on the rear than front, maybe 235 and 255?

Any insight on the OEM ET and max size for oversized tires are appreciated. Again, keep in mind I am a newb, have done some research, but would rather hear first hand from other 1ers. Again, keep in mind in your response I have no ambition on moding the suspension or have any spacers.

[Gangplank]

Best suggestion I have is to search and review the threads.

[one 35i]

This: http://www.originalwheels.com/bmw-wh...8i2013rims.php

You will get an idea of oem rims that might interest you plus you get the size and offset.

Also this will help with accepted tire size for rim(doesn't take suspension variances into account.)
http://www.originalwheels.com/bmw-wh...8i2013rims.php

[mack128i]

Originally Posted by one 35i

This: http://www.originalwheels.com/bmw-wh...8i2013rims.php

You will get an idea of oem rims that might interest you plus you get the size and offset.

Also this will help with accepted tire size for rim(doesn't take suspension variances into account.)
http://www.originalwheels.com/bmw-wh...8i2013rims.php

one35i,

Thanks for the response, however I am mounting custom wheels, not OEM. In the meantime, I have found the OEM offset to be 47 for my wheels. Any idea how much a variance there can be without having any future repair issues?

[BimmerAg]

For stock suspension you can be fairly aggressive with your wheel offset choices. It really depends on the tire size you choose though. If you want to run 235/255 staggered, then a 35-45 front offset and a 40-50 rear offset should work. Of course, this also depends on wheel width as well, so it's hard for anyone to tell you what offset you need if we don't know what wheel widths and tire sizes you want to use.

[mack128i]

BimmerAg thank you for the insight...wanting to run these wheels...the offset is 38

https://www.carid.com/rtx-wheels/env...458893610.html

And these tires

225/40 F
255/40 R

https://www.carid.com/continental-ti...-84033809.html

Could I run a larger ratio in the rear? Like 45-50? I would like to have it as close a safely possible to both the front and rear wells...

[BimmerAg]

Those wheels should be alright with the tire sizes you mentioned. Note that the hub bore diameter is 74.1mm for the 18" wheels, so you'll need an adapter ring for them to fit our 72.6mm hub. I'd be careful about trying to run higher aspect ratio in the rear for two reasons: One, if the front/rear tire diameters are too different, it could affect the function of ABS, DTC, etc... Two, there have been some people that have experienced tire rubbing on the inside part of the passenger wheel well where the fuel filler neck is. I've seen a picture of someone who rubbed completely through the filler neck and had to fill up with a hose and funnel! A taller tire, will make this situation even more likely.

[mack128i]

BimmerAg so...the search continues...did not realize tryna find wheels would be so technical. I don't have a wheel shop in my area, so makes the interweb purchases very nerve wracking...

But if I do go with the set that I posted here, I would have to find somewhere to get the adapter ring...

Have settled on 225 (maybe 235)/40/28 on the front and 255/35/18 on the rear, just got to find a wheel with a 42ENT...

[BimmerAg]

Adapter rings:
Aluminum: https://www.ecstuning.com/b-ecs-part...hoC0sYQAvD_BwE
Plastic: https://www.ecstuning.com/b-ecs-part...BoCqQEQAvD_BwE

[mack128i]

BimmerAg thank you sir!