245/60/15's on 15X8 rims
Is the car small bolt pattern or large? If large, with re-drilled axles or large bolt axles.
A 235/60/15 should work safely with correct backspace and rim width.
235/60/15
15x7
4.25 backspacing
Do not run less backspacing. If you need to make fine adjustments, you can add 1/8”, 3/16”, or 1/4” spacers.
I have 245/60/15 15x7 4.25 bksp in my 68 Dart GT and it is very tight