Chevy learned a lot over the C4 years about handling, and ride control.
In mid-1983 when the 1984 C4 debuted the wheels were 16x8.5 all around on the base suspension, the Z-51 got 16x8.5 on the front and 16x9.5 on the rear. Due to a shortage of 8.5 wheels late in the model year some base suspension cars recieved 9.5 wheels. Wheels sizes remained pretty much the same until 1988, then 17x9.5 wheels were offered on the Z-51 and Z-52 suspensions. In 1989 17 inch wheels were standard on all suspensions.
When the ZR-1 came out in 1990, the tire/wheel combination was 17x9.5 wheels and 275-40/17 front and 17x11 315-35/17 on the rear. The standard Corvette still had 17x9.5 wheels with 275-40/17 Gatorbacks.
This remained so through 1991 model year.
In 1993 the lessons learned from the ZR-1 suspension were brought to bear on the standard suspension, placing 17x8.5 rims on the front on which were mounted 255-50 tires and 17x9.5 rims with 285-40 tires on the rear (except for the RPO ZO7 which had 17x9.5/ 275-40 all around). This combination ensured that base suspension cars would always have terminal understeer, and provided improved handling on the street.
This technology remained the same to the 1996 model year. That year saw the Grand Sport Coupes get the ZR-1 size wheel/tire treatment once again.
I'll end here with the end of the C4 era technology, but I think you get the picture.
The C5 takes tire/wheel/chassis technology to a whole new level, and I'm sure the C6 will astound us with even more fantastic handling / ride control technology.
vettepilot