That sounds a bit strange Rockhampton! what were the problems? and how would a size smaller tyre affect the abs?
A number of cars, including ones with abs have staggered tyre fitment as standard.
I'm intrigued!
Well, from my own experience, when the wrong tyres were fitted, if I braked gently at speed, the ABS would always cut in (chattering on the pedal, brakes snatching). Now I've changed the tyres, that no longer happens - in fact, the brakes are really smooth now. In addition, the ABS lamp would come on about twice a week - always went off when I restarted. It has never happened since the tyres were corrected (the ABS does still function as proven by the recent wet weather!). I've posted elsewhere on the forum, and spoken to a decent mechanic (service manager for an established Fiat dealership), and the consensus is that because the rotational diameter of the front tyres was smaller than the rear, the front wheels were spinning faster at any given speed (about 37 extra times a mile) - this would mean that the ABS was always thinking there was something wrong, and trying to correct. If a car has standard staggered fitment, then the ABS will be programmed as such by the manufacturer (e.g. some BMW models, Smart cars etc.) - the Omega is not one of these cars.
A similar situation arises on some other models if there is a large difference in the wear levels between tyres - this can cause the ABS warning to illuminate, or the ABS to cut in when not needed - looking on the Internet, seems to be a particular problem with some Citroens, and I seem to recall the old Cavalier SRi also.
I can only speak from my own experience - as I say, my braking has improved dramatically now!
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Topic: Tyre sizes (Read 1573 times)