My wife got a new Honda Pilot calling for 5w-20. I was squeamish about the weight (and suspicious of the carmaker's CAFE motivations), but I decided to temporarily overlook the snake oil salesmanship and give Amsoil a try. I first tested it for 1000 mi. in an 1988 Acura Legend which had only used M1 5w-30 till then. I hate to encourage an already overzealous multi-level marketing empire, but I have been impressed. Some cold start lifter noise(even in warm weather) went away and city mileage increased about 1 mpg (about 6%). Oil loss (primarily from minor seal leaks) is on a par with the M1 5w-30. Amsoil is changing to GIII basestocks for this weight, so I hope M1 will make it in this weight. Anyone else have any experiences with this or the other 5w-20's or 0w-20s?