I have DD2's on the dodge and I gained 3 mpg. I just was wondering why? How do you gain fuel economy when you should theoretically loose fuel econ?

 

Are you seeing that on the overhead or did you do it on calculator? If overhead comp was used forget it, they are calibrated for stock equip only, any fueling device will throw it off bigtime.

 

thats what i was using. i never wrote down the mileage and did it that way. dang it.

 

That's what you use to show the wife.<br>&quot;Look Hon.....It's faster AND gets 5 more miles to the gallon.&quot;<br>&quot;If I get that new Comp box, I might even get 5 MORE MPG, ain't these diesels amazing?&quot;

 

My fuel economy didn't change until I went over 400 hp. Then it went down 1 mpg.

 

Mine seems to change daily. Although it seems to go down. :'( Maybe because the throttle is attatched to the floor!

 

The reason the bigger injectors give better mpg, is because the fuel is delivered quicker while the piston is still near the top and the heat is greater. It burns better. The pump will only deliver the required amount of fuel to run at the selected rpm.<br>It can also be described as a fuel delivery/timing issue.

 

As J-Fox said, it's mostly a timing &amp; efficiency deal. In my case, I went from 200 rwhp stock and 15.5-16 mpg to my current power level and getting between 18.5-20 mpg. Can't beat getting 2 1/2 times more power AND 2 1/2 more mpg! ;D

 

[quote author=CMN_NOT_STROKN link=board=7;threadid=6426;start=0#59682 date=1036036514]<br>Maybe because the throttle is attatched to the floor! <br>[/quote]<br><br>LMAO...

 

That's what I love about diesels. You can throw on huge injectors and instead of losing MPG, you gain it. Cams? Same thing. Fueling boxes? They actually defuel you to save fuel while below a certain level. Plus, you don't have to swap from regular to premium gas like you do on a gasser if you put a chip on it.

 

Well since I just put the injectors on, my computer on the truck says I am getting around 19 mpg compared to my usual 15-16 mpg. I am going to figure the math out myself when I fill up but I hope it aint lieing. I like the numbers.

 

When I added 275 injectors, my indicated mpg went up by about 3 to 3.5 mpg, but my actual mpg went up by only 0.5 to 1 mpg. On my truck, the injectors were the only mod that seemed to really change the mpg by a measurable amount.