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View Full Version : BMW wheel and tyre/tire geometry/sizes explained...



genphreak
12-16-2006, 05:10 AM
Attached is a graph of all the wheel dimensions applicable to BMW cars I have been able to find...

Offset, PCD, width, Tires, Tyres, 15, 16, 17, 18, 19 inch - it's all here for your information on exact stock sizes:

UPDATE: Chart changed due to some silly mistakes
Thanks people! Remember, offset is a range- if you stick to the chart you should be ok but you must be very careful exceeding it. Guard rolling should not be required within these ranges. Having to roll the guards indicates you are too close as BMW designs/pre-rolls its fenders with considerable thought at the factory.

Be sure to tell me if I'm wrong on anything... and make sure you exercise caution using this information- I may be just that... WRONG!

In fact if any of you know a lawyer or would ever consider hiring one, take it that all this information is unintentionally wrong and I didn't mean it in any way to be useful to anyone, after all it is probably the general abuse of the legal system that is stopping people from taking any personal responsibilty for anything anymore, especially the planet... such a positive outcome we should all be lawyers so the world could become even better.

Yaninnya
12-16-2006, 07:22 AM
The E30 has 56.1 mm CB and without any problems you can fit 7.5x16 ET30 with 225/45 R 16. Also E34 can run on 245/40 R 18 (on front :D ).
Jan

genphreak
12-16-2006, 09:31 AM
The E30 has 56.1 mm CB and without any problems you can fit 7.5x16 ET30 with 225/45 R 16. Also E34 can run on 245/40 R 18 (on front :D ).
JanThanks for your point Jan. I know e30 hub is smaller... but issed that, Doh!

Thanks. The thing is, just searching around it seems your suggestion of 56.1 might be 57.1mm. Not to nit-pick but I'd rather be right on this.

Also, this list is an attempt to detail known good fitments, a lot of the point here is to ensure a practical clearance, not just get the maximum size under there without rubbing in normal conditions... I am not going to add in sizes that reuire rolling the guards in most conditions.

For example, with 245s on the front e34 I have heard of rub in some cases so for now they have been left off the list.

It's a vague line to draw of course, but ultimately this list is designed to be a list of what you can whack on without doing body mods. It is not including staggered sizes either.

I feel people should choose themselves if they are going further than this as in some it can be a dangerous if it is not really properly modified/thought about. :) Nick

I'll update once the PCD is confirmed.

Qube
12-16-2006, 11:21 AM
Sooooo basically e60, e65 (235) wheels are bolt on? Interesting...

Yaninnya
12-16-2006, 11:53 AM
Thanks for your point Jan. I know e30 hub is smaller... but issed that, Doh!

Thanks. The thing is, just searching around it seems your suggestion of 56.1 might be 57.1mm. Not to nit-pick but I'd rather be right on this.
You can be right. I didn't checked it just used my old hollow memory.

Also, this list is an attempt to detail known good fitments, a lot of the point here is to ensure a practical clearance, not just get the maximum size under there without rubbing in normal conditions... I am not going to add in sizes that reuire rolling the guards in most conditions.
E30 on 225/45 R 16 on 7.5x16 ET30 has a lot clereance. I run on them in my E30. You can go a lot wider on the rear (255 - 265 wide), on front some 245 are not too wide.

For example, with 245s on the front e34 I have heard of rub in some cases so for now they have been left off the list.
It is the matter of offset. That's why I quoted ET in E30 fitment.
Jan

Russell
12-16-2006, 12:40 PM
notice the 2256015 is not mentioned for the e34. It was a standard (535i and 540i) or retrofit tire. Not so sure the e39 m5 ever had 15 or 16" wheels. Or amI misreading the intent of your chart? Anyway, thanks for the chart. I printed it out.

genphreak
12-16-2006, 03:47 PM
notice the 2256015 is not mentioned for the e34. It was a standard (535i and 540i) or retrofit tire. Not so sure the e39 m5 ever had 15 or 16" wheels. Or amI misreading the intent of your chart? Anyway, thanks for the chart. I printed it out.Hey... that's a good point. I don't know how I missed that!

Re M5, you are right. As some people do weird things with winter wheels so I added smaller sizes but its kinda unnecessary.

Chart updated, thanks for the input :)