I have 195/50-15 tyres on my pick up. I just put 32psi in them when inflating, out of habit more than anything, is this about right? more or less?

Here's some info http://www.carbibles.com/tyre_bible_pg3.html not that it gives a definitive answer though

^^ like above, there is no diifiniitive answer tbh, the thing to look out for iis if you have wear on the shoulders of the tyre or in the centre section, you can use this to work out if you need more of less pressure. in my pickup i always use 35psi all round, but i have 13" wheels on there

As a general rule, tyre pressures on non standard wheels should be adjusted by 1.5psi per extra inch over the recommended psi for the standard sized rims. eg standard rims 13" - 32psi means 15's should be 35psi and so on

Thats the reccomendation from a well known Japanese Tyre company I happen to deal with through work...

Do they have any recommendations as to what allowance you should make for changes in wheel/tyre width?

Also, who are they? Citing a manufacturer as the source of information is not advertising.

ah ok, didnt want to breach any regs or anything...Yokohama tyres...sell the odd set of ally wheels where i work

Thanks. As I say, knowing who the info came from is helpful, particularly if you want to requote the info elsewhere.