I had 13" tires on a 63. Could not panic stop at a speed any higher than 45 mph without locking up the breaks and skidding on all 4 tires. Went to 14's and could panic stop from 60 mph no problem. Tires hsd AA tracktion rating on the 13's
I just came to think of something. My 2004 Mercury Grand Marquis does not have very good brakes. But anyway, I had air in the circuit to the rear brakes, and the car would not stop on the freeway. Since it has ABS I can not lock the brakes. In 65 on the freeway and hitting the brakes hard makes the front end dive, and the rear end come up, so you should think it did not matter so much if the rear brakes does not work. I got it fixed, and the brakes works better. But still, the brakes on a Grand Marquis is for Sunday driving. Poop....