anyone feel MPG is better then before? Does FS mean "fuel saving"? Then is a super saving!
I use idemitsu 5w30 before.
FS means Full SAPS, I think. (Or Full Synthetic maybe.)
The 0w40 is thicker than your SN GF-5 5w30. Thicker oil creates more engine friction viscous drag.
More drag means you have to burn more gas to turn the engine. Physics is cruel man.