13mpg pulling my 17' Nomad travel trailer from Vancouver, WA to Sacramento, CA.
'90 D150, 318 and auto.

 

Nice! Do you have the standard 2 bbl? 3.55 gears?

 

Thanks. Nope, TBI and 3:92's

 

i get 12mpg on the city roads while 14 mpg on the highways. i got 1985 D150 2WD
318 c.i.d. V8. automatic transmission.

 

'78 D150 (On '85 W350 Chassis) Carb'd Magnum 318, NV3500 5 speed and 4.10s. Getting 12 city / 16 hwy. Ill update after the EFI 5.9 swap. Coming in the next couple of weeks.

 

91, 4x4, 4 speed 5.2, 355s, 18 or a tad more on the freeway unloaded, not sure round town....I got it Saturday....two days ago.

 

my 88 d100 gets 12ish city, and trailin semis from lima ohio to brighton michigan i average 18. its all stock with the 318

 

i am geting 20 in town and 23 on the hiway ihave a cummins with a five speed over drive

 

Since I have been using my W150 for nothing so far but messing about and one trip to northern new mexico, I have yet to really test the mileage since the first day I got it. I went to Northern NM to **** a rear end for my old Range Rover since I sold it to my buddy and he quickly blew the rear end since he can break an ANVIL with a rubber hammer. We got the rear diff and brought it back and stuck it in and now he is back up and running. I finally topped off when we got back, ran round for about another 120 miles for the two weeks and topped off again. I was doing the happy dance at the pump cause I got 18.4mpg. In a all stock 1991 W150 4 speed (all in 4x2 of course save for a mile of 4x4 testing) at no less than 7500ft above sea level! Pretty dang good!

 

I had my heads rebuilt, replaced the 2 bbl carb that had already been rebuilt twice and replaced the water pump...I am now getting 5 mpg LESS than I did. I have no idea what is going on. The heads are the same ones, just rebuilt due to the dried out valve seals.

8.5 mpg sucks.