Alternate tire size for 21s

[pits200]

Need new rubber on the x50, vehicle came with 375 style wheels which are 10 inches wide up front and 11.5 in the rear.

Running 30 and 35 profile tires looks nice and helps performance obviously but I wouldn't mind stepping up a series. It seems 265 40 21 and 295 35 21 could be an alternative as it stays within 1% difference front an back and increase overall diameter by 1.4% both front and back. And since bmws tend to be fast on their speedo, this slight increase in overall diameter shouldn't bee too detrimental. With the higher sidewall I like how it will give a slightly more compliment ride withoit sacrificing too much performance. Also, I think the tire widths should fit on the rims without too much stretch.

Any feedback would be appreciated.

[CeeTeeX5]

If you don't mind the stretched look that should be fine, but since you'll be stretching those tires on the wide rims, you may lose the benefit of the higher aspect ratio.

[Wavy]

If you want a better ride, I would change to non runflats if you haven't already.

[pits200]

Originally Posted by Wavy

If you want a better ride, I would change to non runflats if you haven't already.

That's what I've been told, I am thinking of picking up a set of PSS. Right now the car is on dunlop rft with about 4/32nds remaining and they are loud and all over the road on bumps.

I know the rfts are bad but are they really this bad?

[Wavy]

In order for runflats to be able to be driven without any air, the sidewall is very stiff and has a bunch of extra support in the sidewall to support the weight of the vehicle. A regular tire will have a more flexible sidewall that will absorb bumps better and will also be lighter.

I have 24" wheels with non runflat tires and the stiffness has barely increased compared to the 21" runflats I had.

[CeeTeeX5]

Originally Posted by pits200

That's what I've been told, I am thinking of picking up a set of PSS. Right now the car is on dunlop rft with about 4/32nds remaining and they are loud and all over the road on bumps.

I know the rfts are bad but are they really this bad?

yes, most people swap out of the RFTs due to ride quality and to put on all seasons. The OEM RFTs also seem to only last about 10-15k from what many have reported. I'm saving mine to put on before selling or trading in.