Tyre laws (One for JR?)

[MattC]

What are the rules and regs concerning tyre fitment? It''s common knowledge that you must have sensible pressure and adequate tread depth, tyres sizes must match on an axle, and tyres mustn''t protrude outside bodywork. MOT tester says that this is all they check (oh, and tyre condition too). But I''d like to know about some other stuff: - Speed ratings. If your car can do 180mph do you need Y-rated tyres? Or do you just need tyres adequate for 70mph? (e.g. many winter tyres are Q-rated) - Load ratings. Lots of people recommend "Don''t fit tyres with less than OEM load ratings." But OEM tyres seem to be rated to support nearly twice the vehicle weight. So what are the rules? - How wide/narrow can you go? Too narrow and you may run out of braking/cornering grip. Too wide and you''re more vulnerable to aquaplaning and stuff. If anybody knows for definite, I''m all ears! (I believe the Road Traffic Act is the key thing. Maybe.) Cheers

[john robson]

I will do a bit of homework, but speed ratings are as per the max speed of car, no real rules in the RTA re width etc get back to you soon.