Synthetic oils

Off the shelf, commonly seen synth oils I use is ethier Castrol or Mobil. Theres others out there. Mobil is a top shelf brand. Amsoil is another that is tops.

I've been useing synth oil in the wifes 99 Ford for about 10 years now. I change the oil twice a year. and filters on the half way point inbetween as well as at the oil change. It's been a bit over a 100,000 miles without issue. Emissions barley rose through out the years which shows minimal wear.