None of the autozone's/walmarts around me have any MX4T. My brother swears by Honda HP4 synthetic blend. Any issues switching to that to see how it works? I wouldn't think so, both synthetics...kinda.
Dan
Well found the problem, it's not MX4T anymore, it's just 4T
http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil1_Racing_4T_10W-40.aspx
"Mobil 1 Racing 4T 10W-40 was previously known as Mobil 1 MX4T 10W-40."
Yeah they changed the name a bit back I heard.. 4T, speaking of I have to change my oil, of course I have to run the valves too LoL.