Are 205/40 ok on 17" alloys?
 

Are 205/40 tyres ok to run on 17" wheels or should they be 215 or 225?

Depends on the wheel width 17x7(wrx) usually go with a 215, 17x7.5 (sti) usually go with 225.

There team dynamics motorsport wheels. I just went and measured the wheel width and there 17x7.5"

the tyre of choice for 17" wheels is the 205/45/17,gives a slighty more balanced ride ,however they are not available in great numbers and are more expensive.I have bf goodrich gforce profilers on my 17s and they are great!

But is there anything wrong with putting 205/40/17 on the wheels i've got, i friend said to me that i shouldn't put them on and i should get 215/40/17 because 205's will affect the handling and would never handle as it should?

A 205 section tyre may be stretched slightly on that width rim and therefore may not handle quite as the tyre maker designed it to. I originally had 205 section on a 7" rim, they used to 'track' all over the shop and wouldn't ride the road surface well at all. Changed to 215 and all was sorted:)

They will be perfectly fine. I have used 205 section tyres on 8" rims, admittedly thats the max but i suffered no ill effects.

There is always an ideal width but a size either way is perfectly acceptable.

wasnt the p1 with 17" wheels fitted with 205/45/17?

Yup

i have 205/40/17`s fitted on mine and have had no problems at all.

And I'm also pretty sure the original versions were 7" wide, ideal for a 205 section tyre.

Still, I suspect from the replies that the tryes I were referring to had other issues rather than the fitment side:)

I guess in a way, by using a tyre on a wider rim than it should ideally be on, will give sharper turn in as the sidewalls will be made even stiffer? Just my thought though.

if using 205/40/17 tyres, won't it come off the rim while hard cornering under acceleration due to the low profile?