In my Liberty, I've always ran Dino in the diffs. Was told on the Jeep forums (and read it on a few of the high end axle builder's sites) that Dino sticks to the gears better and therefore dissipates heat better than synthetic. The liberty has 222k miles on it on the factory axles running 85w140 in every condition, so I guess it worked! I'm looking to change diff fluids on my JL Wrangler soon and am wondering about that debate again. Is that just a myth or outdated thinking?