I use
synthetic oil in 4 different cars, An 85 K car(0W-30), an 88 Porsche(15W-50), an 93 Taurus(5W-30) and my 2000 SPF(5W-30). It did not cause any of them to leak. I would favor the Mobil1 since they don't have 500 web addresses trying to get you to use their
oil like
Amsoil does.
Use the lightest weight which provides the pressure you need. This will maximize flow and cooling. Using 20W-50 with an
oil cooler at street temperatures is tough on flow and cam gears.
Bob