MPG Test in latest Diesel Power

Has anyone else seen the Dmax & old 2wd Dodge without OD getting 27mpg?

Its in Diesel Power so it must be true:hehe::hehe:

Its in Diesel Power so it must be true:hehe::hehe:

Should loan em my truck & see what it can do. :doh:

Man, I’m bummed. I wish I could get in on one of these tests where everyone drives a road trip at 40 MPG to post big numbers. Ol’ dummy Dave beats his brains out trying to get good MPG while driving a third of his tests on city/suburban streets and blasting down the highway at the posted limit.

Give me a flat road with no stops and let me drive 800 RPM in fifth gear and I bet I can get over 35 – maybe 40.

I reckon it would help if I lived in California – where the media is.

holy cow, I just noticed you were up to 27mpg Dave.... Awesome!

I read that today.

I read that article too and really wondered how legit it was? Seems almost BS, but there's a lot I might be missing...

I dont get the mag anymore just because of dumb stuff the put in there like that.

I haven't seen the article yet. What were the parameters they used?

Well, it sounded like the only constant was that they all topped off at the same time. It said guys were doing the old tricks of shaking the truck or jacking the drivers side up so they could get as much fuel as possible into the tank. Then they drove a predetermined course in whatever economy tune or tune of choice that they had. So there was a wide variety of mods in the different trucks from almost stock to high HP. Then they all filled up at the end to see how much fuel they used. But I bet none of them shook their truck or jacked the one side up when they filled up at the end... :bsflag:

I thought is was a bunch of :bsflag:

Well, it sounded like the only constant was that they all topped off at the same time. It said guys were doing the old tricks of shaking the truck or jacking the drivers side up so they could get as much fuel as possible into the tank. Then they drove a predetermined course in whatever economy tune or tune of choice that they had. So there was a wide variety of mods in the different trucks from almost stock to high HP. Then they all filled up at the end to see how much fuel they used. But I bet none of them shook their truck or jacked the one side up when they filled up at the end... :bsflag:

you know in the diesel power challenge's I kinda thought the same thing..

I bet he didn't do that crap when he refilled..

Is that the challange where the winner did not have to account for all the propane he used?:bsflag:

I still haven't made heads or tails of this article.

I haven't seen the article but I can get about a 3-4 gallon difference if I shake my truck to fill it all the way up or just when the pump stops... That is the difference between 23-27...

I haven't seen the article but I can get about a 3-4 gallon difference if I shake my truck to fill it all the way up or just when the pump stops... That is the difference between 23-27...

Harpoon your tank and you will only be able to get maybe 1/2 to 1 gal more in after the pump stops. Honestly, I thought I had a 25 gallong tank on my truck until I harpooned it. Now I can pump 29 gal. before the pump stops(on an almost empty tank of course).

As an owner of a Harpooned tank I agree that having the tank harpooned lerts you fill quicker and more consistently.

Having done A LOT ofd MPG testing, my opinion is that if you are sweating how full you get the tank, your test is too short to be of any accuracy. To me, at least thousand miles is necessary (1,500 is better) for an accurate picture of your fuel consumption.

Of course if somebody wants to spring for high-precision volumetric or gravimetric systems, I would change that tune.

This summer I have figured that 1 gallon off on a fill-up is equal to about .75 mpg difference.
Best way to figure mpg is to average out over many miles, multiple fill-ups...

Harpoon your tank and you will only be able to get maybe 1/2 to 1 gal more in after the pump stops. Honestly, I thought I had a 25 gallong tank on my truck until I harpooned it. Now I can pump 29 gal. before the pump stops(on an almost empty tank of course).


I tried searching the threads. What is/what all is involved in harpooning a tank?

Basically you drop you fuel tank, remove the sending unit, reach inside with a pair of PVC pipe cutters and cut the fill tube and return tube as close to the top of the tank as possible. I can post pictures when I get home, or you can go HERE (http://guzzle.rbmicro.com/harpoon.html) and see a write up on the procedure...

Thanks Ramblin' Man. With this I may be able to get closer to 40 gallons. Looks really simple.

Is that the challange where the winner did not have to account for all the propane he used?:bsflag:

For what its worth that guy lives less than 10 miles from me....and his Duramax freakin rocks!!! He made over 600 HP in the same tune that he got like 39 MPG. BTW, That is NOT PROPANE... Its compressed natural gas. I believe there is a difference...

Here is a Link to the place where Jeff Dean Bought his kit
Home Page...
http://delucafuelproducts.com/index.htm
Photo's...
http://delucafuelproducts.com/photo.htm
Explanation of CNG vs. Propane...
http://delucafuelproducts.com/Compressed%20Natural%20Gas.htm

they don't have anything specifically for us 7.3/PSD owners the best I can tell. But it looks like it could be addapted. No prices either.

Is CNG supposed to be safer for the engine vs. propane? I am assuming that CNG would also ignite before the diesel injection if it goes into the air intake creating an uncontrolled ignition issue?
Would the main difference between propane and CNG be the cost of the fuel itself or are their different burn characteristics between the two?

Natural gas has a very low cetane rating. Like propane, it has to be "blowtorched" into combustion in a compression-ignition engine.

Interesting.