depends on the wheels, 15x7's had i believe g60-15's, which are said to be about like 235 or 245/60/15's.
thought they used the same size on all 15x7s and 14x6s.ou: heres a conversion chart btw. http://www.tirerack.com/tires/tiretech/general/size_conversion.htm
tires guys: friend of mine in 1970 purchased a new skylark. tires were f78x14 (black steel rims) . the h78 series was for the station wagons . g78 & g70 ,were optional, but u need 6 inch rims . we are talking canada here . i owned a new 70 chevelle malibu, back then. i purchased a set of 14x6 rims and installed a set of h70x14 glass belted tires. what a difference in handling & ride ! always wondered why the car manufactures always undersized the wheels and tires when all the rodders & engineers knew from experience that bigger was better . gerry 72 buick gs ht
