What's the average acceptable fuel mileage on a 1998.5 Cummins 4x4 5speed stick. The truck is totally stock and runs well, just loves diesel. What can be done to increase fuel economy?

 

i have an 01 24v HO with 6 speed and i was getin 14 mpg then blew the head gasket and replaced it and i checked my valve lash and there were many that were way way outa accepted spacing i had a couple over 30 thousands off so i evened all of them to corect specs and now i get 22 so maby check ur valve lash, then id start upgrading programers intake exhuast ect... good luck and hope that helps

 

I have an '01 24v with an auto tranny, edge juice with attitude, intake and exhaust. I'm gettin 13 on the mileage setting...would the valve lash be something you think I should check into? The truck has 170K, is there anything else I should check out to help the mpg's?

 

It says on your Cummins Maintenance book that you should check your valve lash at 150k so you might want to give it a once over anyways.

---AutoMerged DoublePost---

Heres a video by DieselMinded on valve adjustment to help you along.

https://www.dieselbombers.com/dodge-...ent-video.html

 

I have an auto but get 22 on the highway, 16 around town. Manual should get at least that.

 

my truck with 150 hp sticks, and some other stuff is getting around 17to 19 in town/country. Highway I can see about 22 mpg. not bad if for a 450 hp truck wieghing 7800 lbs without me in it

5sp manual, SB DD and 305/70/16s

 

would mileage very with gear ratio?

 

yes depending on your tire size

 

Yes mileage can vary depending on gear ratios and tire size as well

 

echo.