14 to 15 in wheels?

Hi Id like to upgrade from the hubcaped 14'' factory rims with 215/75 14. To some factory mag 15x7's. So the question is- what size tire would I need to use to obtain the same overall tire diameter as original.

 

optional 15" buick rallye rims came with G60x15 glass belted tires which are equivalent to 245r60x15 tires.

 

Try this calculator to get the size you need to switch from 14" to 15".... http://www.miata.net/garage/tirecalc.html

 

I have an original owner installed HR-78 14 (A P-metric 215 equivalent) mounted on a Buick Rallye rim out in the garage. It is about 27.5 inches tall by my tape measure. The 245 60 15 (which is also out there) is around 26.6 inches.


Here is a helpful chart: http://clubs.hemmings.com/clubsites/chevylist/tech/tire_size_conversion.htm

 

Thanks for the help, it looks like the 245/60-15's are the ones I'd want.