I have been racing my 911 using only Mobil 1 and it never failed me is such extreme conditions especially in the Texas summer heat... I can't imagine why it would be not good for a truck that goes through a lot of thermal stress especially when towing.
BTW I also use Mobil 1 on all my cars. In my wife's bimmer I switched to Mobil 1 and no more lifter noise that I used to have at start up with the generic BWM oils...
Just my '02
