Correct Closest Tyre Size

[billy]

Hi all,
Some advice needed....
Would like to change my 14 inch rims for 17 inch. According to the common and garden tyre calculators that are on the net, the closest match for me (for the size I would like), is 205.40.17 (front) and 225.40.17(rear).

Only thing is, every site I look at stocks plenty of 225.45.17, but none of the 225.40.17 ratio. If I go for the the easily available ones, is it going to make much of a difference? The main point being either 1.66% out 225.40.17, or 5.4% 225.45.17 out, compared to original set up.

I guess what I am really asking is how far out dare you go, percentage wise ( I know, the speedo will be wrong (ish)).

Any advice gratefully accepted,

Thanks

Billy

[michael]

215/40's up front and 235/40's at the back works well.

If anyone in the Leeds area wants some trackday tyres I have some 205/40/17s and 215/40/17s taking up room in my garage:

http://www.megaboost.co.uk/tyres/

[billy]

Brilliant!
Just checked, and there is plenty of choice at that size, and only 3% out from original diameter.
Thanks for the advice!

Have a great xmas

Billy

[Andy Jones]

If you wanna keep the rolling radius the same as the o/e tyres when stepping up to 17" then a 205/40 front, 215/40 rear is the closest possible match.

As you've probably seen, 225/40 is not available. The majority of people seem to avoid running 215/40's on the rear cause they aren't as wide as the original rear's. So 235/40 is a popular choice but does knock out your speedo reading slightly. If your going for 8x17 rims on the rear you can fit 245/35's - These have virtually the same rolling radius as a 215/40.

HTH

[billy]

Very good advice.
Appreciate it.
Going for 235s on the rear. Like the sound of them!
Regards
Billy

[paul_h]

Very good advice.
Appreciate it.
Going for 235s on the rear. Like the sound of them!
Regards
Billy

I run 245 X 35's on the back seems to stick that little bit better then the 235's. Might be all in my head but they are a closer match than the 235 x 40's when talking about rolling radius


paul