Every manufacturer is going to recommend you use “their” fluids. I suppose you can’t go wrong doing this, but you can get just as good of oil elsewhere, cheaper. Maybe the exception being with ATF+4 and Chrysler transmissions. If Mobil actually does make Toyota-branded oil, buy Mobil instead and save some $$. I can understand them wanting people to use Mobil-1 with some sludging problems a matter of record on some motors.