How to improve fuel economy on Cummins 24 valve

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MG93108

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Santa Barbara
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1998.5
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Cummins 24 Valve
Hi
I'm new here.....
I have a 4x4 1998.5 24 valve with a 5 speed manual stick shift transmission and 4wd
Right now I'm getting 20MPG with an empty bed
I know that is actually pretty good but I hear others say that they do better.
I'm not as concerned about performance as I am about the MPG's.
Is there a simple adjustment? I'm not really wanting to spend thousands of dollars to save hundreds of dollars. :)
Thanks for your help
 

mtnrider

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20mpg is pretty good, i'd be happy with that. All those people out there that claim to get extraordinary mpg's ... I take that with a grain of salt and wonder how well they did in math class? (lol)
I see the same thing with my 4th gen cummins. everybody and their brother is getting ~16mpg but there is always that one guy claiming 25mpg. When you have 100 people getting 16 and 1 getting 25 I think it's pretty easy to figure out who is correct.

I don't think there is much else you can really do. Keep the filters clean and your foot out of the pedal, speed below 65 etc.?


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MG93108

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Cummins 24 Valve
20mpg is pretty good, i'd be happy with that. All those people out there that claim to get extraordinary mpg's ... I take that with a grain of salt and wonder how well they did in math class? (lol)
I see the same thing with my 4th gen cummins. everybody and their brother is getting ~16mpg but there is always that one guy claiming 25mpg. When you have 100 people getting 16 and 1 getting 25 I think it's pretty easy to figure out who is correct.

I don't think there is much else you can really do. Keep the filters clean and your foot out of the pedal, speed below 65 etc.?
.

OK!!! Sounds real good. I've been teaching math since 1982 :)
I'm getting 600 with 30 gallons of fuel. First time was on a straight freeway only run. The second tank was the same mileage in mixed driving conditions. I do tend to "Keep my foot off of it". Although it will take off pretty well, I tend to be a pretty conservative driver.
Thanks for your reply
 

Marine Les

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5.9 cummins/3.6 Pentastar
I have 2000 5.9/ 5spd since new. MPG depends on speed/rpm/load. Empty, driving 50 highway I get 23 every time. At 65 I get 20 and at 75 I get 18 all with no load. I keep a record on a notebook of all fuel and miles. I almost always pull a trailer with a big cabover and get 14 to 15 driving easy. Beats all the best gassers when pulling.
 

WY-Dave

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Move to WY and only go east. the west winds push me to 24/25 hahaha
 

chri5k

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If there was a "simple adjustment" to gain a few mpg, one would think FCA would have done it from the factory. They did make one adjustment to 4th Gen's, a Cummins 6.7. That engine is 800 cc's larger, has more torque / horsepower and gets as good or better fuel economy than the 5.9.
 

crash68

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I see the same thing with my 4th gen cummins. everybody and their brother is getting ~16mpg but there is always that one guy claiming 25mpg. When you have 100 people getting 16 and 1 getting 25 I think it's pretty easy to figure out who is correct.
That one person might be getting 25 mpg but let's just say they wouldn't break a half cracked egg if it was between their right foot and the accelerator pedal...lol
Then there is the Canadians who inadvertently calculate fuel economy using UK gallons instead of US gallons, that's good for a couple miles more per gallon.
 

Billythe kidd

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You might try a Edge Tuner, as it has 5 settings and the first two may give a better ratio and get some more MPG. My truck I just bought came with an edge tuner and I have it level 1, and gonna see how it goes MPG wise.
 

13Goat

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Got an '02 2500 Laramie, 5.9 with the 6-speed manual, 3:55 rear gears.
It was usually good for around 18-19 mpg if I kept it around 60-65 highway. We pull a 30' bumper pull, probably gross out 10k. Local diesel shop encouraged me to put marine injectors in--told me I would pick up mpg and torque. Didn't see how better fuel economy and more torque could happen, but it did. Towing, I picked up a couple mpg (up to about 13-14) and a noticeable amount of torque. She don't bog down on a long incline nearly as much as before.
 
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