I use PP. I got this for free...also QS Truck and SUV, Mobil Clean 5000, Valvoline SynBlend or something or another, all free with rebate. Come on, it was free! I'm going to use all of them, one brand at a time, in one of my Subaru's. The other will get a steady diet of the PP I've stashed (at 1.99 a quart average cost). Both engines will probably outlive their transmissions.