sounds crazy to me

I prefer synthetic.
After an engine i saw opened up after 40,000 miles that had Amsoil in it all of the time, and was a 440 with a .509 mopar performance cam with the related springs etc. The cam and lifters still looked like brand new.
He by no means was easy on the engine, and the only reason it was opened up was because he bent 2 push rods over revving it doing one of the many burn outs in the car he does on a regular basis.
Well, i sure hope we don't get into that debate again.....