ticki2,
Our 2004.5 D/A CC LB 4X4 was approx 1/2 mph fast with the 245 OEM Bridgestones when the ordered truck came in. Therefore, it's 4+ mph slow with the 265's when they are new as comfirmed by our GPS many times.
I have had a total of 4 sets of 265 Michelin LTX's on the last 2 trucks so far including the new one's put on Fall. All have been on the optional chrome plated steel OEM 6.5" wide wheels we order and never had one single problem in over 250,000 miles so far of heavy TC carrying and 5th wheel towing. It's all our trucks are ever used for!
I can't speak for other brands of 265 tires because I've not used them but ours wear even all across the tread. I am careful not to corner at high speed as being an retired automotive engineer, I know what it does to tires! Who in their right mind would turn a corner fast with a 12,840 lb weighed 5th wheel behind or an 11'4" heavy truck camper on the back anyway?