New Toy With 6.2

[randynoguts]

 

got me a new (to me) toy. a '84 m1009. diesel blazer to your civilians. drove it home 500+ miles and got 17.8 mpg on the first tank (mountains and level) then 18.8 on the second tank which was mostly mountains and then around town for a few days after i got home. very happy! its in very good shape over others i have seen. i collect military vehicles and have a m35 with a multifuel turbo. i know what to do to take care of her, but what about this light duty non turbo? same heavy duty oil? or can i go lighter for a bit better mileage without hurting anything? i run 15-40 in the big truck can i go to something like a 10-30 in the 6.2. ? the motor has 80k on it, as a referance, imean who really knows with surpluss. it could be the 3rd motor. thanks in advance for any input you may share! randy

[randynoguts]

well i got no response to my question so i decided to go with my gut. i went with rotella 15-40. at least all my trucks will be on the same fluid. reading the manual for the truck it stated straight 30 weight. but that was a long time ago and oils have changed since then. so hopefully it wont mess things up.