BMW E85 and E86 Wheels and Tyres Thread

[Mr Tidy]

Welcome to the forum with your smart looking Z4.

If it makes life easier a jack from an E46 BMW will fit the jacking points on your car, and so would a space-saver from an E46. Don't forget you'll need a wheel-brace of some sort too.

Or like Zedebee said you could get another full-size wheel to match yours. It will take up more space in the trunk, but if you ever fit a space-saver the wheel you take off will take up the same amount of space!

[Deadken]

Thanks for the input.

I'm waiting for a E46 to come into the junkyard that I use.

I did look under my car and I see the 'jack pads'. I had assumed that it would have a jack point on the welded seem where the lower sill is welded to the floorpan. I was wrong. When I get the spare / jack / lug wrench from the E46, I'll have a chance to verify that everything works before paying for it.

What do you mean by needing a wheel-brace? Are you saying a 'chock' or something to keep the car from rolling while being jacked up?

Good points, I'll have to see if there is anything on Ebay or in local forums (I'm in the USA if you didn't notice the front plate holder in my photo). I'm not sure where else to find one matching rim. Any suggestions would be appreciated.

[Mr Tidy]

Thanks for the input.

I'm waiting for a E46 to come into the junkyard that I use.

I did look under my car and I see the 'jack pads'. I had assumed that it would have a jack point on the welded seem where the lower sill is welded to the floorpan. I was wrong. When I get the spare / jack / lug wrench from the E46, I'll have a chance to verify that everything works before paying for it.

What do you mean by needing a wheel-brace? Are you saying a 'chock' or something to keep the car from rolling while being jacked up?

Good points, I'll have to see if there is anything on Ebay or in local forums (I'm in the USA if you didn't notice the front plate holder in my photo). I'm not sure where else to find one matching rim. Any suggestions would be appreciated.

The jacking points seem to be the same on most BMWs. The E46 jack I got fits my E86 and my E90.

Wheel-brace is what you refer to as "lug wrench". Two nations separated by a common language!

[Deadken]

I finally got a spare tire from the junkyard that I have a credit with (I returned an item and couldn't get any cash back). I can't recall which year and model that the spare came from, but I do know that it was NOT an X-Drive car (from what I have heard the all wheel drive wheels are different from the rear wheel drive wheels). Junked E46's don't seem to be to common or aren't bought at auction by the junkyard I am dealing with.

Upon comparing the two wheels, I see that the spare is a bit taller diameter than my tire (almost 1/2" diameter, so about 1/4" bigger in radius). All I can guess is that the newer cars have slightly larger wheels / tires.

I removed the rear wheel and it bolted right up and had a good offset (not tucked too far inside the wheel well). I will try it out on a front wheel when I have the time to get it out of the garage.

Now, what I'm wondering is if anything will happen to a limited slip differential with a wheel that is almost 1/2" taller. My current tires are 225/45 R17 on 106 rims (turbines?) and the spare tire is 135/80 R17. When I check the tire sizes out on the 'will it fit' website, I can't get an exact difference in the diameter or circumference because I don't know the rim width's.

Any information or suggestions would be greatly appreciated.

Exactly! The subtle differences between the way Americans and the English use the language always intrigues me. I like the 'our' vs 'or', ie: Colour is better that color. What I do find funny is the differences in pronunciation of the word Aluminum

[Mr Tidy]

I don't see why the rim width matters .

A 225/45 tyre will have a sidewall of 101.25mm (45% of 225) and a 135/80 will have 108mm of sidewall, so the actual diameter of the space-saver will be 13.5mm greater than your 225/45 tyres. But I don't know if that difference would be enough to upset an LSD. Maybe the solution if you got a puncture in a rear tyre would be to put a front wheel on the rear and fit the space-saver on the front?

BTW we pronounce aluminium the way we do because that's how we spell it!

[Deadken]

Earlier on in one of the recent posts, someone suggested using the 'will it fit' website. While using that website, I found that changing the rim size would vary the angle of the sidewall, apparently enough to vary the diameter of the wheel. Simply put, I'm sure that the website is of help to some. I tried using it, but it didn't work so well for me as I didn't have all of the data requested and I didn't want to guess at the width of the spare rim.

I'm a bit happy with myself as my 1/2" guess would put me right around 13mm and that is pretty close to what you figured out

Thanks for doing the math for me. I appreciate the insight / information.

I considered only using the spare tire for the front, but swapping things around would likely require assorted pieces of wood (which I don't have the trunk space for) or two jacks (which I wouldn't trust the stability of). I guess if I do get a rear flat, I could always reach out for roadside assistance and let them use their 'real' jack (with one of those little cup adapters, so you don't crush the jack receiver on the underside of the body).

There you go, one more little bit of difference. I'm sure that the few little differences are all because our founding fathers did not want us to speak 'the Queen's English'. Now, don't get me started on units of measure!