Tyre Size question

Guys and Gals,

Generally speaking, if I fit 18" alloys should I reduce the tyre profile to 35......i.e 225/35/R18?
 
spot on by the raptor :thumbup1:

within 2.5% and you will be fine

35% tyre sides are very stiff - makes it "lively" over bumps and B roads ;/
 
Cheers Raptor/Foxspeed....got the chance at some Ultraegras 18" 225 wide which have been run on a 197 previously...interestingly, they are currently fitted with 45 profiles which I would have thought would rub under the wheel arches and altered the tacho/miles??
 
225/45/17 is no problem, speedo is still slightly behind what the gps says... Space in the wheelarches is also sufficient for that size.

Edit: Ah...you have 18 inch wheels in mind...so tyre size is 225/45/18? That definetely won´t fit!
 
with 18's you will find the lock to lock reduces drastically ure car will turn like a range rover. a 3 point turn will b a 5 point turn :worried:
 
...seems I've been too late to get these 18" anyway now....so I'll keep looking for a set of 197 17" wheels......