Brownedog wrote:
My tyre placard reads 20psi front and 26psi rear loaded for standard 205 tyres on sierra.
Seams a little low for every day road use to me what do you think?
Cheers
IMO 26 PSI is too HIGH for the rear at any time. I run 22PSI all round for highway with 215/75R15s whilst LOADED within 100kg of the GVM.
If you run 31"s you can get away with 15PSI on the highway!
Reason. Light car compared to the relatively large (i know only 26" right) tyre size- e.g. coily softop is only 930kg. Leafy/1L are a bit lighter again - about the same as an hyundai x2 excel which has 155R13 as standard - except the sierra has whopping big 205/70R15 to carry it's 930kg.
As a comparison - from memory a VN commodore has 205/65R15s (a tiny bit smaller than sierra) and is 1800kg so it needs 36PSI to support that weight!