I love it so far(have nearly 2000 miles on the first run in my saturn) and have no complaints. Mileage seemed to be down at first but I'm getting the best Ive ever gotten in this car (2001 44k miles) at this point. It is also quiet on a cold start and seems to idle pretty smooth. Ill save my complete endorsement until I compare a UOA with it against Amsoil. I think oils like Amsoil, Mobil1, GC and a few others are all good oils, my only problems with Amsoil is that it was still a little noisy on startup but not near as noisy as Mobil1. My UOA on Amsoil looked great at 4k miles. When the Amsoil run is done in my Tacoma i will be doing a UOA and filling it with GC to compare in the truck also.