Bart,

I just found shop with a couple of good guys, and they are pushing the "green" thing. They use Amsoil exclusively and I recently had them replace my front and rear diff. fluid, transmission fluid, and transfer case fluid with the stuff. Apparently Amsoil has been "synthetic" since like 1920 (it's a corn based lubricant) and it's supposed to last forever. Well, not really, but Amsoil states that the transmission fluid is good for 500,000 miles. They also state that their oil is good for 25,000 miles between changes. There are some additives that you have to pour in every now and then, but that's about it. I didn't do the oil because I just don't trust a 25,000 mile oil yet.

Anyway, all of that is to say that when they where changing the fluids out they said that the old stuff was in fantastic shape and could have gone another 70,000 miles (the VX just turned 70k after Moab). To my knowledge those fluids where never changed by the previous owner so it seems like Isuzu put some good stuff in there to begin with.