I have the Vrs estate with 18 inch wheels. Anyone with similar experimented with tyre pressures yet? If so what do run at for normal load/driving and what do think is the benefit?

Also have the same as you.

Most of my mileage has been with the car empty except for me. Most of my mileage has been long distance motorway work.

Done 26k and fronts have been replaced, the rears are getting near replacement, probably another couple of thou. Ran 31 psi front and tyre wore evenly. Backs have been run at 30psi and the wear patten suggests it is under inflated, so probably needs to be 32psi at the back.