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Discussion Starter #1
OK, before the search Nazis get me, I have used the search feature. The tire size posts I've seen deal with wether or not a certain tire fits under the well, or on the stock rims, etc...

I need to replace all 4, and want to go a little wider if possible. I also want to maintain the stock ratio for ride height (I bow to the BMW engineers in this regard).

I'm attaching a spreadsheet with some tire sizes, but the closest seems to be 255/40 - 275/35

I wanted 255/35 but a Tire Rack rep said the .7 in drop in the front could effect braking at highway speeds in such a heavy car.

Has anyone been through this, or is the common thought just 'stuff it in there'? (or am I being OCD?)

Thanks,
-D
 

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OK, before the search Nazis get me, I have used the search feature. The tire size posts I've seen deal with wether or not a certain tire fits under the well, or on the stock rims, etc...

I need to replace all 4, and want to go a little wider if possible. I also want to maintain the stock ratio for ride height (I bow to the BMW engineers in this regard).

I'm attaching a spreadsheet with some tire sizes, but the closest seems to be 255/40 - 275/35

I wanted 255/35 but a Tire Rack rep said the .7 in drop in the front could effect braking at highway speeds in such a heavy car.

Has anyone been through this, or is the common thought just 'stuff it in there'? (or am I being OCD?)

Thanks,
-D

On the fronts, check the load rating. Stock hi po tires are around 94. If the 255/35 has a similar rating (say, 93 or better and proper speed rating), I wouldn't be too concerned.

1 size up or down is typically OK. Rears may be tight with 285/30. Might need to roll the fenders.

Rear tires that are within a few percentage points won't be noticeable on effective gearing (taller tire has the effect of putting in taller gears; shorter tire, shorter gearing).
Regards,
Jerry
 

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I have 255/35 in front and 285/35 in the rear, on 18" BBS rims that are 1/2" wider than stock. No rubbing at all.

Dennis
 

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Discussion Starter #5
what are the stock sizes that come on the front and back??
245/40/18 and 275/35/18

What I was focusing on was not wether a size would fit (I've rolled the fender and stuffed 295s on a 350z), but to avoid changing the aspect of the car.

Just by going to 255/35 - 285/35, the difference in height is almost an inch. Not an inch as in lowered evenly an inch, but as in the front end is lower than the rear by an inch with regard to the stock dimensions.

255/40 - 275/35 was the closest match, but I ordered the stock sizes anyways.

-D
 

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I have 255/35 in front and 285/35 in the rear, on 18" BBS rims that are 1/2" wider than stock. No rubbing at all.

Dennis

Dennis,
Can you elaborate on which bbs wheel you have? I recently purchased a used set of BBS Lm reps, 18"x8 and 18"x9. Offset is 20mm for both. The guy I bought them from indicated the tires sizes were 225/40/18 fr, 255/40/18 rr.
That's smaller than the stock size. I would think I could install larger than stock sizes without issues.( same as you're running)??
Thanks,
Will
 

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I run 275/35/18s on all corners. I do get some tram lining but the grip is worth the trade off. You should go to the tire manufacturer's web site and check the wheel width range the various tire sizes will fit. There are many variations of staggering and consistency on this board. Good luck.
 

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I'm concerned that the rears will rub. Given the stock rear wheel offset is 22mm as opposed to 20mm. I don't think I'll have a problem running 275 in the rear ( only 2mm difference) , but I want to make sure.


Thanks.
Will
 

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I'm concerned that the rears will rub. Given the stock rear wheel offset is 22mm as opposed to 20mm. I don't think I'll have a problem running 275 in the rear ( only 2mm difference) , but I want to make sure.


Thanks.
Will
Will, My wheels are BBS RK 2 piece wheels purchased from the tirerack a few years back. I'm not sure of the offset I'll have to check the paperwork at home. I could have ran a stock sized tire at the back, but since the rims are 1/2" wider I got 285's mainly for aesthetics, (I don't like the look when the tread is not as wide as the rim).
 
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