Question

ABS - Tyres size exchange and how it affects ABC

Answer 1

if the diameter of the tyre of any wheel changes, there can be a difference in the rotational motion of that wheel which may surpass the critical threshold leading to ABS taking matters into its own hands when it does not need to. But, if all four diameters are changed, I believe ABS may still be affected even though there will be a difference in the rotational speeds of all the four wheels leading people to believe that it might not affect the ABS as the difference now would be the same as earlier. There is a reason why car companies come up with specified tyre diameters as these diameters are set in the ECU as well. So changing tyre diameter essentially leads to a change in the threshold potential but the threshold potential fed in the ECU is according to the old tyre diameter. This can cause trouble in a special case of tyre slipping when your difference in wheel rotations does not outrun your threshold potential, but outruns your luck.