I use Royal Purple in my Supra..........I use Mobil 1 on all the rest of my vehicles. I get Royal purple for free because they sponsor my friend's car so that definitely helps with the cost. I probably wouldn't use it if I didn't get it from him. However I'm not sure if most of you know or not but Mobil 1 Synthetic is not a full synthetic, its a blend. Its widely debated whether that is good or bad, however it works for me so I still use it. There are also differences in eastern and western oils. Oils from the eastern United states have a tendancy to make more ash......which leaves some residue in your engine, companies like Penzoil and Valvoline or was it Castrol? Anyways, Mobil is probably the best you can get out there for just a basic oil.