No 2 loads of gasoline from the tank farm are exactly alike and with changing weather, traffic and our driving making a mileage judgement is not much more than an accurate guess.
Originally Posted By: Eugene_Von
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.
I switched from M1 5w-30 to the M1 0w-40 old version last year. That's even thicker than the new FS stuff. Can't say I've seen any change in MPG since the switch. From winter to summer up north here, air density varies from 10-14%. That should be a change you should notice with other variables fairly constant.