245/45 tires on an 8" rim is OK. I'm no expert but I believe having wider rears than fronts has something to do with improving handling charateristics of a vehicle. If I had 8" rims all around, I would probably go 235s on all rather than 245s. but thats just me. Never had a 245 on an 8" but I would assume there would be a bit more tire bulge compared to a 225 or 235.