I put synthetic in the rear end and transfer case and my MPG went from 12 to 17, anyone else have that big of a jump just from synthetics?

 

I'm glad to hear that. Cause I was thinking of doing the same hoping to get a few extra mpg's. Didn't think it would make that much of a difference tho... Sure you calculated it right?

 

Oh and what brand/weight of oil did you use?

 

I don't remember the brand, but it was 90 wt in the rear, and synthetic atf in the case

 

I'm running synthetic in the engine, tranny, front and rear axle and I didn't gain squat in mileage or power. Your just lucky.

 

i think that is some kind of freak accident....lol, been runniung it in mine since first oil cchange...in everyhting like big blue too, and didnt notice one change...same with my last truck...hope fully this one lasts as long as that one( i imagine the amsoil helped out alot)

 

You must have added a RFG aling with that oil change?
(Right Foot Governor)

 

I have been running Amsoil ATF in the Transfer case and syn in the rear end for a while, and did not see an increase at all.

 

what did you have in there before 1,000,000,000,000wt gear oil?