will 225/50/15 fit on 7.5 wide wheels?

can i go larger?

Yes and probably.... the bigger question is whether they'll fit under the fenders. I can't answer that.
Mark D.

i'm not worried about fenders, this tub is going to get flares

stock SCs and Carreras in the '70s and 80s ran 225s on 7 inch rear rims.
perfectly fine to run 225x50s on 7.5 rims.
You might want to run those up front and run 8s or 9s in the rear with 245s, since you will have flares.
225s on 7.5s will look kind of lost on the rear with flares.

I ran 225x50x15s (DOT Rs which are usually wider than street tires) on the rear of my 914-6 under stock (massaged) fenders

here it is with 225x50x16s on 7s on the rear for street use

That is one sick white beast. Never have been into white until now

Yes the tires will fit the rims. as to bigger tires good luck in finding a bigger / better tire.

Rather have better narrower rubber than big fat crappy tires.

I KNEW IT. I knew there were people putting 225s under narrow body cars, but I posted a thread about it (since I want to do it myself) and I got a whole in-rush of people saying, "No you can't do that... The biggest you can go is 205 and that's even a stuff-job." Did you have to do any sort of custom spacing to fit the 7s and 225 street tires under the rear? I assume you rolled the fenders a little. Sorry for the hijack, George.
Mark D.

yes the lips were completely rolled and the fenders themselves were pulled out quite a bit....it takes some time and some effort but they fit.
Fender work was done by a local body shop.
from the side it looked completely stock. from direcly in front of from the rear of the car you could see the definite extra bulge of the fender to allow the 225s and 7s to fit.
no spacers, 7x15 or 7x16 wheels with 225s for track or street.

Here is my car a couple years ago with 15X8 with big fat 205/50/15 Hoosiers. They barely cleared both sides. Dont let anyone fool you - it does take some work to get fenders pulled out to make everything fit and not all 225 tires are created equal when it comes to width. I'd make sure you go with a 225 that has a more narrow spec for width.

george, you have seen my car.

225's on 8's under massaged fenders.

good luck finding a 245 to fit a 15.....in any series...of any quality
seems like good year, dunlop and bf are the only makers....
i don't belive the compounds to be any good
i think yoke makes a 225 for the 15 and me thinks that is the best you will do
for the street....
next step is a 16....and then the options open up
but i am stuck on my 15 bbs mahles so it will be 225
but i intend to flare any how and runs spacers to push them to the lips
that is the plan so far....
but it is subject to change