Fuel economy.

[matt-jenkins]

So, Today I calculated my fuel economy worked out that I got 320km off of 60L of fuel. Roughly 198 miles and 16 gallons of fuel, That works out to 12.4Mpg.

Isnt this pretty low for these trucks? I dont think my driving habits are to blame, I am pretty easy on the go pedal, air filter is clean, what else could be sucking back so much fuel?

 

[1994IDI]

You didn't tell us what kind of driving you were doing, but that is the same economy I get in the city with the truck in my sig, always between 12-13 MPG. The only difference seems to be your auto tranny to my ZF 5, if you have a turbo. So your numbers seem normal to me, but others may have a different opinion.
Then I get about 16-17 MPG under 60 MPH, and 14-16 over 60 MPH.

Hope it helps.

 

[SparkandFire]

I've been told that a tired pump and injectors can help you toss more of your dollars at OPEC and Saudi Arabia...

My truck is probably running around 12 as well, but i've got a C6 and I would think the pump/injectors is pretty tired.

My brown truck had a solid 15 mpg average, but it was lighter.


How old are your fuel injection components?

 

[ghunt]

I'm getting about 14 mpg on mixed driving with the summer fuel...during the winter I'm usually around 12-13.

I've got 107K on my original IP and injectors, but that's a lot of dough to fork over right now to replace them...

 

[BioFarmer93]

Eureka!

I've figured it out! See your avatar photo, and all that black unburnt fuel pouring out your tailpipe? See in your signature where it clearly says "pump turned up two flats"
But, then again like previously mentioned it *could* just be fuel system wear..

 

[matt-jenkins]

Perhaps It could be just a tired fuel system, I bought the truck at 370,000 and I dont know when the Pump/injectors were replaced. Could be brand new for all I know but what are the chances of that, I'm guessing they are getting pretty tired.
I was just under the impression that it was normal to average at least 15 or 16mpg daily driving.
ignore my ignorance, carry on lads.

 

[david85]

Is that for one strait shot at highway speeds? or is that a lot of short trips of 10 miles or less?

 

[ghunt]

I don't think I've ever done better than 14, even on a long highway trip at 65 mph. 15 would probably be a stretch.

 

[fury9]

do you have a turbo?

 

[matt-jenkins]

Is that for one strait shot at highway speeds? or is that a lot of short trips of 10 miles or less?

Its pretty much the same highway or city, and for the person who asked, I do not have a turbo.

 

[creighta]

local driving wmpty I get 14 year round. On the highway around 60mph I get 18mpg.

Loaded stock trailer on the highway gets me 10-12mpg depending on how many hills I have to climb.

It looks like our trucks are pretty similar except for the turned up pump. Mine even came from Canada originally.

I bet turning your pump down a flat would help. New fuel system could never hurt either.

 

[david85]

Its pretty much the same highway or city, and for the person who asked, I do not have a turbo.

Yeah somethings not right there. Are your fuel injectors painted grey? If so that means they are original from factory and well beyond their service life. Even if not, you might still consider having the injectors pop tested by a diesel injection shop. The shop in my town does this for free, not sure about others.

Having the fuel turned up isn't helping but its hard to say if thats playing such a big role here. If you keep an eye on your side mirror, are you seeing any smoke when you are up at cruising speed?

 

[burtcheca]

My '86 E-350 w/ C6 has everything still factory parts (including injectors and IP) except of course filters. It's a custom van, weights 9,000 pounds and give me 15-16 MPG under 60 MPH.
My '86 F-350 4WD w/ T19, weights 11,000 pounds and give me 12-14 MPG.
I would like to add a turbo to this truck, maybe next year.
Burt.

 

[93cc7.3]

i guess i get above the norm 18 city 22 hwy just rolled over 300,000

 

[pybyr]

I bet turning your pump down a flat would help..

For guys like me who want to maximize MPG, and I generally don't need a ton of power-- would turning my pump down a bit beneath stock go anything-- or, I assume, I'd get the same results by "staying out of the pedal" a bit more?