Just like many other models, the Saab 9-3 had a variety of possible disk rotor sizes. You'll need to know the correct size to order when replacing discs.
One option is to jack the car up, remove the wheel and measure, but on models newer than 2006, there's a much easier way.
This documentation details how to decode the VIN plate in order to identify brake disk and caliper sizes on Saab 9-3's.
If you open the passenger side door, you should find the VIN plate in the lower part of the door way. Along the bottom is a string containing the brake codes
The format of this string is
n-nn-nn-[front disk]-[rear disk]-[Front Brake Caliper]-[Rear Brake Caliper]-
Where the various alpha values for each of these is as follows
- AA 15", 285mm disk
- AB 16", 302mm disk
- AB 16"+, 314mm disk
- AD 17", 345mm disk
The size of the front disks can also be verified by looking at the leading edge of the front calipers, which have the disk size (in mm) stamped into them. Depending on the wheels you have fitted, you may be able to see this through the spokes.
- BA - 15", 278mm disk solid
- BB - 16", 292mm disk vented
- BC - 16", 292mm disk (XWD)
Front Brake Caliper
- CA - 15", 285mm
- CB - 16", 302mm
- CC - 16"+, 314,,
- CD - 17", 345mm
Rear Brake Caliper
- DA - 15", 278mm solid
- DB - 16", 292mm vented
So, for example, a code of 2-41-60-AB-BB-CB-DB- has 16" Front Wheels, 302mm disk and 16" Rear Wheels, 292mm vented disk.