A lower tyre pressure will help a tyre to conform around an object making it less likely to puncture. It also has the advantage of providing some extra shock absorbtion on corrugations, but make sure you lower your speed also. I have Cooper STT 245/75/16's on my D1 and normally run them on road at 32 front 36 rear. When towing the van I run te rears at 44 and the van at 45-50. I have taken the van down the GRR on a number of occasions (last weekend being the latest) and drop the fronts to 28, rears to 38 and van to 38 also. Keep the speed under 80kmh and have not had one single tyre (or other for that matter) problem yet. In that time I have passed many a shredded tyre on the side of the road and also quite a few vehicles having to sort out tyre failures.
