18" Alloy questions
 

Im wanting to bue some BK 238 for my 98 impreza but im wantiont to no firts how the wheels size will change the speedo reading and will if afect the breaking in any way.
also what do you do about the spare wheel when you have a flat as the size differance between the alloys and the spare. will it efect the AWD system.
thanx

When you put a bigger wheel on you need to reduce the tyre depth so that the outide circumfrence does not change.
eg 17inch wheel as 215/45/17 put a 18inch on tyre size should be 215/40/17
the 215 bit is the width 215,225,235 and so on.
If you dont follow his rule then your speedo will be out
eg bigger circumfrence speedo shows slower readings than actually travelling but the wheel/tyre will fill the arch better.
powerman