On the Mobile1 site it says: "Mobil DEXRON-VI ATF is recommended for 2006 and newer GM vehicles and improved performance in 2005 and earlier vehicles, wherever DEXRON is specified."
On the Castrol - DEXRON-VI: "Certified and approved by General Motors for all cars and trucks that require DEXRON®–VI. Also satisfies requirements of DEXRON®, DEXRON®–III H, III, IIE, and II."
My mother does a lot of driving on gravel/country roads and maybe 25% city driving with half of that 25% stop in go. Also she has people with her most of the time, so the car has more weight to it. We live in a pretty hilly area too, with a lot of hills to climb. Her transmission does a lot of work. I just want to get the best for her.
Seems more people are leaning towards the Castrol one. Please give more suggestions, I need the help. Thanks!