1st Generation Dodge Cummins 89-93 Discussion of 12 Valve 5.9 Liter Dodge Cummins Diesels with Rotary Injection Pumps

90' 12V 5.9L Cummins Power & MPG

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  #11  
Old 02-01-2011 | 04:49 AM
cumminsblazer's Avatar
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How does two stroke give better milage?
 
  #12  
Old 02-01-2011 | 02:05 PM
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From: Princeton, NJ
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First off, the myth of a bed cover or removing the tailgate has been expelled a while back. The air actually comes over the bed and forms a bubble which helps push the truck along...you negate that by removing the bed from the equation.

I think Mythbusters took a truck to Lockheed's air tunnel to bust that one.

I also have a w250 with all the same fixins as you.

I have yet to see anything I do improve my mileage. They're just big ol' bricks going thru the air. I keep hearing that timing will add a few, injectors will add a few, better flowing intake/exhaust will add a few.

Well, I've got all of that, and you know what? It's been the same since I got her. A lot more fun to drive, definitely, but 17ish MPG all day long.

---AutoMerged DoublePost---

PS - 2 stroke oil won't necessarily give you better mileage, but it will lube your fuel system like it was 'sposed to be back when these trucks came out and low sulfur diesel wasn't something you had to worry about.
 

Last edited by Subliminal; 02-01-2011 at 02:05 PM. Reason: Automerged Doublepost
  #13  
Old 02-01-2011 | 11:17 PM
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Never heard the 2 cycle oil, but a very wise diesel guy told me to dump a quart of automatic trans fluid in the tank every month or so.... says it cleans the inj. and burns any carbon out. But more than 22 or 24 MPG with any diesel is un-realistic. best i ever got is 22 with a 94 12v turning about 300hp. and that was running about 55-60 MPH and bein real nice to 'er. If you put un burnt fuel in the air or cruze too fast (over 1800RPM) depending on your gearing you wont get very good milage. the same guy as earlier claims on his life that if you exceed 1800 RPMS you will drop 2 MPGS. i called him out and tried myself, i felt like a jackwagon, it's true.
 
  #14  
Old 02-04-2011 | 07:01 PM
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Goldies getting around 22 mpg now that it's cold. Last summer I was getting almost 700 miles to a tank(25 gallon) I drive slow, 28 mpg. I swear my Nano filter gave me 1-2 more. I love it!! I think the B-fuel kicks it up a knotch too
 
  #15  
Old 01-17-2013 | 12:45 AM
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I have had several Cummins, My first a '96 Dodge 3500, automatic. I was averaging around 21 on the Interstate. I live in northwest Florida. About 6 months after purchasing it I purchased a LARGE slide in camper in Wisconsin, and had to remove the tailgate to go get it. I was amazed, I checked it with a calculator, the mileage jumped to 27mpg. The return trip, loaded, checked at 20mpg. I ran the truck most of the time from then on without the tailgate, and the 27mpg remained constant. I will say this, I am not in any hurry, I never ran it over 55mph
 
  #16  
Old 01-17-2013 | 09:47 AM
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Things like big tyres, tyre pressure and whether the front axles have locking hubs all affect mileage, even light bars above the roof line.
Very hard to compare different vehicles.
 
  #17  
Old 01-17-2013 | 11:09 AM
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From: TorqueWrench City
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Things that will improve your fuel milage are as follows:
1. Keep your tires aired up,
2. Lower your wind resistance,
3. Keep your filters clean and trucks PM done,
4. Run synthetic lubes....gotta be careful here, some of it will leak past your seals,
5. Propane injection, a small DIY Kit can cost, oh, $100 or less, and give you a extra 4 to 6 MPG on average.
6. WMO....lubricates and burns well.

Back in the 20's and 30's, there was not diesel fuel, as we know it. There was fuel oil, bunker fuel or oil. Diesels were origionally designed to run off waste oil in cotton mills, bean mills, (Cotton oil, canola oil, linseed oil).
The Automotive industry started selling the left over less refined oil as diesel way back when to get money for their left overs.
Its been such a long time, everybody has forgotten that these motors were designed to be effecient running off leftover oil.

Search Rudolf Diesel and look at the history of the Diesel Engine.....

---AutoMerged DoublePost---

Theres a Kickass propane system writeup here, everyone serious about getting more mileage out of their trucks need to read it....

---AutoMerged DoublePost---

http://www.dieseltrucksite.com/showthread.php?t=676
http://www.cumminsforum.com/forum/89...injection.html
 

Last edited by Screamin' Metal; 01-17-2013 at 11:15 AM. Reason: Automerged Doublepost
  #18  
Old 01-17-2013 | 09:46 PM
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From: Salt Spring Island
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I've considered putting my old '93 injectors in my spare '90 engine donor (6 smaller holes vs. 4 larger holes) with the use of the 7mm-to-9mm adapter washers. Fuel should burn better that way... might increase economy.
 
  #19  
Old 01-20-2013 | 08:42 AM
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Do NOT run ATF, it now has no burn compounds and detergents that can be harmul to your engine. 2 stroke oil is at least supposed to burn, but imho Marvel Mystery oil is the best additive. My '03 24 valve got some every 1/3 tank and I'm about ready to put some in my 12v. Stanadyne makes an excellent diesel additive as well but you see more difference in newer vehicles and it is pricey.

I've ran diesels for years, cars and trucks, the only problem I've ever had is with the powerstrokes. I reuse to spend money, however, adding something every tank when that money can go into upgrading my truck

The best way to achieve mileage is to have your vehicle running properly, maintain your tires, suspension and pumpkins. Put an electric fan in instead of a clutched one. Look to your motors, not your gas tanks. And tonneau covers are solely for filling your bed with beer, they don't help mileage.

Just my two cents......
 
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