What kind of fuel mileage do you get?

[highdesertrange]

1978 k30 crew cab dually, 454, 465 trans, 205 transfer, 4.10's. low 5.5 mpg, high 9.2 mpg. the 5.5 comes in fully loaded towing up mountain grades, the 9.2 comes going down same grades. highdesertranger

 

[MannyDantyla]

83 K10 4x4, 35" tires, 350cc w/ SM465... 7mpg

unknown gear ration but I suspect it's stock because the engine is gutless up hills (hey I just bought it, will perform HotRod's technique for calculating it soon though)

 

[one4fun]

1986 K10 short bed, 350, 700r4, np208, I believe it has factory rear end. 3.08, G80 locker, 33/1250/15. 10 city/12 hwy.

 

[Stepperado]

All right, after some attention it's getting better..........

Last tank was 15.1 mpg. This is mostly driving back and forth to work on country roads, not a whole lot of stopping, and cruising around 50mph.

84 shortbed, 305, TH350C, 2.73.

When I convert to a 700r4, I can see this being close to 17. Maybe 19 on the highway? Only time will tell.

 

[MannyDantyla]

Replaced the spark plugs and wires.

Before: ~8 mpg highway
After: ~14 mpg highway!!

City mpg is still awful because the new fuel pump is overflowing the Edelbrock carb at low RPMs. A Holley fuel regulator is on the way, will be here tomorrow. Should help tremendously.

edit: just calculated the gear ratio:
- 3.42:1
- 35" tires
Thats why highway mpg is so good! and driving around the city is so bad! lol