Thread is getting thin on my original firestones, yet they're still working amazing well in the snow we just received. Have to to make a choice between the same size all season kuhmo's, more firestones, or goodyears. I plan keeping the tire weight, and size close to the same as what came on the truck, so I don't hurt performance, or fuel economy which has been excellent.
I've spoken with a friend thats a toyota master tech already about tires. He's told me these gen3 3.5's with the differential ratios they come with are very sensitive to excess tire weight, that toyota has sent out each trim with the best epa fuel rating while taking Into account what the truck was designed mainly for. The sr, sr5, and limited is biased more for highway use, while the trd trims more for off-road....said neither should deviate from the tire weights, and sizes they came with unless willing to accept loss's in fuel economy, and performance.