Nissan GU 3 Patrol 4.2TDi Tires

Have had Silverstone AT 117's fitted to our Patrol for 57000km and there is still about 2.5mm to the wear limiters. 80% of our usage is on bitumen towing a 20ft tandem caravan with the remaining work commuting on bitumen and gravel roads. Have rotated the four tires every 10k or so and obtained very even wear, best pressure found to be 36psi rear & 34psi front. The tires run very quietly and have not required rebalancing, no punctures or damage either. We're about to replace them with the same since we're off shortly on another big caravan trip. Paid $200 ea for them over 3 years ago and have now been quoted $175 ea for replacements; hard to go past that!