Bias or radials? Please help this newbee!

[Willie]

According to my charts the revs per mile of a 520X14 crossply=865
The revs for a 145X14 per mile=892.

[minor_hickup]

So not a huge amount of difference when it comes to speedo readings? Do you have the revs/mile for 155/80s, just out of curiosity?

[wiglaf]

Glad to know I'm not the only one running tyres half way between the manual's recommendations and the fitters' recommendations - and with no ill effects apart from a slightly squishy look. I did try them at the full modern 30psi, and it didn't feel like they were gripping the road quite the same. Firestones all round.

[alex_holden]

Mine still look slightly 'squishy' with 32 on the front and 30 on the back. On Saturday I had a random bloke at the traffic lights shouting at me that I needed to put some more air in the front one. They seem to be wearing OK at that pressure though and they have loads of grip. 28 was definitely much too low. 145x14 Bridgestone Ecopias.

[Willie]

Yes, revs per mile for 155X14" (assume they were 80 s as they were Dunlop SPs)=873.