I'm on the 3rd oil change already in my beast, 2nd oil change they did put Pennzoil in it, the 3rd oil change I ordered Motol 0W40, 3500 miles on this new oil already and I've noticed a difference in the engine sound, and the temp gauge is lower by 1 notch as well. I haven't checked my MPG recently but I did notice I've picked up 12 miles per 1/4 tank of fuel with the Motol oil.

Going to stick with the Motul oil for awhile, I already ordered 2 more cases for the next oil change , and I called suncoast and ordered 4 10K service kits, 2 20K, and 1 30K to have in my garage ready to go. I'm almost positive I'm going to rack on the miles on this thing and push it to it's limits in a short period of time. The way things are going with my traveling. I'll have 75-85K on this thing within a year of owning it. It's been rock solid so far, just stupid things ( software and hatch door rubber seal so far).

 

This was exactly my experience in Alaska. Mobil 1 poured like oil even in the winter in Fairbanks.
I saw more engine failures there with Royal Purple than any other oil, though I'm hesitant to say it was because of the oil. The folks using it had a tendency to turn up the boost.