I only go by results..... usually with oil most people never get to see any real results. I was lucky (if you call wasting obscene amounts of money on a race car, lucky?) enough to see the insides of engines that ran on Amsoil. I could look at the bearings, the cylinder wall and see a difference. Also we could measure the difference, by time, and by the reduction of friction. This was measured not only in the time but in temperature. The Amsoil would reduce the friction, there by reducing the heat it caused. We can see that by oil temperature gages. Also when I replaced the ATF in my transmission, I saw an immediate reduction in ATF temps, by 30-35 degrees. The Quads we run, do very well with Amsoil. The 2-strokes really pick up power, you get reduced smoke and better plug life. I am not any kind of a scientist, but I don't real think it takes one to read a gage or look at a time slip.