14" bbs with 15"

[polsta]

How much difference would it make using a 14" bbs wheel as a spare, if you had to put it on a car with 15" bbs on, in a "to get you home" situation , would it depend on the tyre profile ?

[Rich320I]

not much i dont think mate, iv got a 14inch bottle top as spare and run 15bbs 195 50 and as luck would ahve it had a flat and ran the bottle top for a few days didnt notice anything

[chh137]

Far better than a space saver,and safer.

[BenHar]

Go here and check the sizes: http://www.etyres.co.uk/tyre-size-calculator.htm

Get the closest to the same that you can.

It will be fine then as a get you home spare.

Ben

[polsta]

what size is the bottle top tyre rich ?

the other option would be a 15" bbs not a space save, reason i ask the tyre thread continental talk reminded me, i have a perfect oem finish 14" bbs with a conti premium contact tyre thats like new, wheel looks like its only ever done the odd few miles from new, it was a spare in a car i had, was gonna list it for sale but it would look great in a boot, and if i should use it as the spare and hope i never have to use it

[polsta]

Go here and check the sizes: http://www.etyres.co.uk/tyre-size-calculator.htm

Get the closest to the same that you can.

It will be fine then as a get you home spare.

Ben

thanks for that, il check what size tyre is on it

[Rich320I]

il check for you later mate but the bottletop is on whatever ever size is standard for that wheel from BMW,

think youd have to be running a wheel of a sainsbury's trolley to notice a huge difference anyways

[B7]

Bmw never changed the diff ratio between cars with 15" or 14". Neither did they run a different dash chip to ensure speedo reading was right. The gearboxes all had the same ratios when 14" were fitted as when 15" were fitted.

Thats because the rolling diameter is the virtually, if not the, same between a 14"with the correct spec tyre (which I believe was a 195/65R14 IIRC) and a 15" with the correct spec tyre (205/55R15).

I'm sure someone will come along with calculations to bore us all but bottom line? You bought exactly the same mechanicals whether you had 14" or 15" rims. So you won't notice any difference either. As long as the tyre size is correct.

[capnmchl]

http://www.willtheyfit.com/

You have the wheel and tyre sizes, you tell us?

[polsta]

Bmw never changed the diff ratio between cars with 15" or 14". Neither did they run a different dash chip to ensure speedo reading was right. The gearboxes all had the same ratios when 14" were fitted as when 15" were fitted.

Thats because the rolling diameter is the virtually, if not the, same between a 14"with the correct spec tyre (which I believe was a 195/65R14 IIRC) and a 15" with the correct spec tyre (205/55R15).

I'm sure someone will come along with calculations to bore us all but bottom line? You bought exactly the same mechanicals whether you had 14" or 15" rims. So you won't notice any difference either. As long as the tyre size is correct.

good info thanks, hopefully thats the tyre size !

[verde]

Mate drove around with 17s on 40s and one 15 on a 55 for a while and had no issue, you wont have a problem just going to a garage

[sunnyr83]

Why not just buy a 5th 15"?

[polsta]

ive got a couple of sets of 15s, but this wheel looks the business in the boot as a spare being like brand new, would of sold it if no good but il keep it for the spare