Looking to see if I should size up or keep same spec tires on my 18x9.5 +22 front and 18x10.5 +15 rear rims. Currently running 245/40 and 275/40 and from what I read I heard I could go 255/40 285/35. Good idea to size up into these specs will I be rubbing anything up front? 06 coupe stock ride height dont think I will be dropping anytime soon or at all.
I want the tire to fully fill the rim out this is currently how its looking:

 

I've got 245/40/18 and 265/40/18 on I think mid-20 offest Enkei TS09. 18x8.5 and 18x9.5. 265/40/18 is a pretty perfect fit on 9.5, and I bet you could clear at stock height (I've got a good amount of room with 245/40/18 up front and I'm lowered a bit. Just looking at my car, I could easily fit another 4mm front and 8mm rear in tire height). You should be fine on stock height, but I'd whip out the tape measure just in case.

 

Sounds good going to size up and see how it goes.

 

Just use an offset/tire calculator and a ruler to see if you have the clearance. Just make sure the difference in diameters between the front and rear is less than a 3% difference.