Some posters have said the Walmart Supertech synthetic is a good group III synthetic - that it is better than your average dino, but not as good as Mobil 1, Amsoil, Red Line, etc. Which oil company makes Supertech? If I stuck to oil change intervals between 3000 and 5000 miles, would this be a better alternative to a synthetic blend? I'm not looking for super-extended OCIs, so Amsoil, Mobil 1 EP etc would be a waste of my money. Thank you in advance.