Hello, new to the forum. Long time reader. I’ve been reading up on everyone’s mileage per gallon and I’m embarrassed. I can pull 12-14mpg empty. Mostly highway miles, running in my level 1 fuel economy tune. Granted my truck having wide wheels and being leveled doesn’t help. But 14mpg just isn’t right. I was wondering if anyone had tips or tricks for me? I drive pretty nice to get these numbers and I want to do something about it. I know there isn’t a 100% way to get 20+ mpg but I should be getting better than this don’t you think? All my mods are in my sig.

The biggest thing I'm learning is most people are doing thing backwards. IAT optimally should be above 80*F and below 140*F. Cold air will crank up an excessive amount of timing. Most Fuel economy tunes are heavy timing advancement but since I can see your signature at this point I'm not sure what I'm working with tuner wise. Injector pop pressure is a factor MPG number there is quite a bit of study happening right now and experimenting with pop pressures as high as 365 Bar when stock is 310 bar. I would get your signature filled out and we will dig into this more.

1999 24v Cummins

-Fass 150

-quadzilla adrenaline 1000 series tunes

-Water/Methonal injection

-20x12 Moto metals on 33’s

-Leveled

for some reason my sig isn’t showing up

If you have Iquad you should update to V2 tuning.   

 

If you don't then run aroudn on highest level,  that will get timing high enough to get good mpg.  I am betting your timing is sitting at ~14* while at cruise,  it needs to be at ~20*

Is v2 tuning hard to upgrade to? What does it all include? I’m decent with computers but not with custom tuning. Never really messed with it

 

It's not hard  

the tuning is easy to get started with.  
 

Biggest perk is it offers you the ablity to control timing and fueling.

 

Sounds good, I’m gonna try an get it going this weekend and see if I can get her some. Any good mileage tunes? For a basically stock truck with a tuner?

Stock injectors?

Tunes you can download are here  

https://mopar1973man.com/forum/185-standard-quadzilla-adrenaline-tunes/

and you'll need an app for your phone that you can get at play store or here, preferably android for phone and get I quad BT if you have an android 

http://quadzillapower.com/iquad-module-for-adrenaline/

This will replace your old monitor that came with quadzilla originally. Unless you already have all this. 

Edited January 17, 20187 yr by Dieselfuture

3 hours ago, CTcummins24V said:

Stock injectors?

Yes stock injectors 

31 minutes ago, Dieselfuture said:

Tunes you can download are here  

https://mopar1973man.com/forum/185-standard-quadzilla-adrenaline-tunes/

and you'll need an app for your phone that you can get at play store or here, preferably android for phone and get I quad BT if you have an android 

http://quadzillapower.com/iquad-module-for-adrenaline/

This will replace your old monitor that came with quadzilla originally. Unless you already have all this. 

Already have the iQuad app and everything, I just need to update quadzilla box to v2 tunes.

Time for some injectors most likely. I swapped mine oe for RV275's and pickup about 1.5 mpg. I have 50's in now and did not see any drop. You have a lot choices with the quad and I defer to those smarter than I for advice on size.

 

Your tire and wheel combination is not helping. They are taller and wider than the stock tires. The taller and heavier they are will detract a good bit from your MPG. I am running stock 265"s on alloy wheels and a Comp and getting 19.5 on the interstate.  

Basically, if the injectors have over 100k miles you should think about replacement. I've seen people go much farther on stock injectors but the quality of spray goes downhill quick. Like When DAP tested my stock injectors even though they run fine they are mere 240 Bar at the worst injector stock is 310 bar. Even though they still run the 240 bar is just to poor if atomization for the quality of efficiency.

6 minutes ago, Mopar1973Man said:

Basically, if the injectors have over 100k miles you should think about replacement. I've seen people go much farther on stock injectors but the quality of spray goes downhill quick. Like When DAP tested my stock injectors even though they run fine they are mere 240 Bar at the worst injector stock is 310 bar. Even though they still run the 240 bar is just to poor if atomization for the quality of efficiency.

Think 7x.010 injectors are too big for decent mileage? I’m looking at a 362/68/12cm turbo. I don’t want to run too small of injectors and lean it out. But I also want to keep drive ability

3 minutes ago, SIlver_Bullet1997 said:

Think 7x.010 injectors are too big for decent mileage? I’m looking at a 362/68/12cm turbo.

1

 

You might want to look at some of the conversation about high pop pressures and some of the Quadzilla tunning. Like myself I'm running an HX35/40 Hybrid (60/60/12), +75HP (7x 0.0085) Injectors and using my daily tune I'm reaching 21.06 MPG 

 

5 minutes ago, SIlver_Bullet1997 said:

I don’t want to run too small of injectors and lean it out.

 

These are not gasoline engine there is no such thing as lean mixture. You can be overfueling and creating black smoke but no way to lean it out. Typically you find your high MPG in those places. My typical engine load is mere 20-22% at 65 MPH compared to stock which could be as high as 30-35% engine load. Now Engine Load is equal to the amount of fuel injected.

Use the tuning to control your injectors.  Go bigger than smaller, MPG is a result of your right foot and your tuning.  

 

I am running 7 x .012's on a he351ve and still topping 20 mpg highway pretty easy. so 7 x .010's are too small for a 62 in my mind. 

My next set will probably be in 150hp range whatever it is 7x11 maybe, I got 62/68/12. Running 75hp now it's good power but I easily max canbus out with no smoke at all. Now if I didn't have v2 tuning I'd be in 60-75hp range, that's why I have these injectors, got them a while back before v2 stuff.

2 hours ago, Me78569 said:

Use the tuning to control your injectors.  Go bigger than smaller, MPG is a result of your right foot and your tuning.  

 

I am running 7 x .012's on a he351ve and still topping 20 mpg highway pretty easy. so 7 x .010's are too small for a 62 in my mind. 

So 7x.011 or 7x.012 is the question for a 62/68/12

Quote

20x12 Moto metals on 33’s, Leveled

 

Also, consider your rolling resistance and leveling kit adding to the wind drag. 33" is rather minor but still moves the final gear ratio down lower below 3.55 and puts more stress on the drive line. Like in your case to keep the 33" I would consider 3.73 gears to bring the ratio back. 

On 1/16/2018 at 11:06 PM, Me78569 said:

It's not hard  

the tuning is easy to get started with.  
 

Biggest perk is it offers you the ablity to control timing and fueling.

 

So I looked into v2 tuning. I’m upgrading my box this weekend. But I’ve looked through the list of tunes and nothing about mpg tune? Just daily and race tunes along with some tow tunes

 

as long as you keep timing in the 19* +-1* at 55-75 you will get good mpg.

Might look at my daily tune its designed for MPG as a goal.