Tire size question?

I was wondering if 285 and 305 tires were the same size?? When I looked for 285 Pro Comp tires they went from 265 right to 305 and I couldn't find any 285's. Are they both size 32.8? Also, is it really true that 15 inch rims don't fit on 99 chevy's???

check tire specs should tell you overall tire diameter, depends if 305/60 or 305/75 ect., pretty sure you need a 16" rim to clear brake caliper.

IT is true that a 15" will not fit. Also, the 305 and the 285 are the same height, the tread area is just a bit wider onthe 305/75. It is the equivilent of a 33x12.50x16, as the 285 is a bit narrower.

thanks.