Tyre Pressure for 33x12.5xr15?

what sort of tyre pressure should i be running with 33x12.5xr15 tyres on a defender 90 , not towing or loaded ? would around 25-30psi be suitable ?

I run Khumos in that size, generally 28-32 on front and 32-34 on the back.
Harry

thankyou , i'll try that out

Have you tried the chalk test?

Draw a (fairly thick) line across the tyre in chalk and then go for a drive.

If the chalk wears out more in the middle than the sides = tyre is overinflated
If the chalk wears out more on the sides than the middle = tyre is underinflated
Even wearing down of the chalk = correct pressure.