I have an Amsoil dealer where I truck out of...he's been bugging me to switch...and I don't see anything wrong with their product...just have used Mobil 1 for 20 yrs now, with no complaints...there are some other products out there, I use in the motorcycle, and I have tried Redline products in the cars as well...I think as long as they are rated well and synthetic...they are good products...I change mine in November of each year...I drive about 4K a yr....