I'm wondering how sensitive the ABS system is on our cars. I know it's the most crude version out there but my question relates to using tire sizes other than stock. I was hoping to put a little wider tire on the back. I can get a pretty good deal on some Hoosiers that are 275/45-16 for the back and 245/45-16 for the front. I have 9" clubsports on all four corners and normally run 245/45 all around. With the 245's having a circumference of 77.7 inches and the 275's having a circumference of 80.5 inches the there is about 3.5% difference in rotational speed between the front and rear. With the rears being on one circuit of the ABS (IIRC) I'm not sure if this difference will result in false ABS triggers. Anybody have any experience or info? Thanks.

 

As I understand it, if your difference in rotational speed between the front and rear is less than 4% you are ok