From the Puma owner's guide:Standard Puma
(195/50 VR 15) - Psi
(Bar):Up to 100 mph and short time driving over 100 mph:
Normal load, up to 3 people: Front 29
(2.0), Rear 28
Full load, more than 3 persons: Front 37
(2.5), Rear 41
(2.8 )For continuous speed over 100 mph:
Normal load, up to 3 people: Front 32
(2.2), Rear 31
Full load, more than 3 persons: Front 40
(2.7), Rear 41
After market alloys in 16" or 17" will usually run happily on about the same pressures as 15" wheels.
Whilst there is nothing technically wrong with inflating your tyres one or two Psi above the recommended, it must be remembered that to overinflate your tyres can cause problems.
Over inflating the tyres causes the outer edges to lift away from the road, meaning you have less of the surface of the tyre in contact with the road. This will decrease grip, and increase the amount of wear in the middle of the tread.
Underinflating tyres will cause the side walls of the tyre to take all the pressure. The outer edges of the tread will wear more quickly, and grip will aldo be compromised.
This website: http://www.dunlopdriversclub.co.uk/tyre ... /tyreCare/
has a helpful guide for indentifying the cause of even tyre wear.