Crappy Mileage No Matter What Tune

[TheGreatWhite]

37 minutes ago, dripley said:

I was hitting 20 psi on mine with a 3" section of intake gasket blown out. But 30 to 32 used to be my norm. Fixed that but another has arisen and I need to pressure test again. Thought I found it with the inter cooler boot.

I haven't done the test in awhile but I might do that later today. I have a weak spot in a boot on the hot side charge pipe that's through the rubber top layer, but I've tested it before and it's shown no buddles? Could this be the issue?

Edited December 27, 2019 by TheGreatWhite

[Me78569]

This isn't tune related.  Load is too high to get good mileage, assuming it wasn't windy and it was realitively flat.

[TheGreatWhite]

1 minute ago, Me78569 said:

This isn't tune related.  Load is too high to get good mileage, assuming it wasn't windy and it was realitively flat.

Well I live in the Flint Hills so it's semi flat, but when it's not the hills are quite the pull, but in that log yes it was relatively flat with one semi good hill.

[Royal Squire]

Some flatbeds are very heavy. Don’t know about yours. 

[TheGreatWhite]

3 minutes ago, Royal Squire said:

Some flatbeds are very heavy. Don’t know about yours. 

Its not even for a Dodge funny enough, but I don't see how all that steel could be lighter than sheet metal. The underside is made of I beam, C channel, and square tubing. I have a bed for the truck, just need to cut this one off the frame sadly :(.

[TheGreatWhite]

Here's a better picture on how far out the flatbed sticks out.

[dripley]

How heavy is the truck?

[TheGreatWhite]

23 minutes ago, dripley said:

How heavy is the truck?

7800-8000lbs I believe

[TheGreatWhite]

3 hours ago, dripley said:

How heavy is the truck?

Actually closer to 9k, found some receipts.

[dripley]

2 minutes ago, TheGreatWhite said:

Actually closer to 9k, found some receipts.

I was wondering. It is not odd for me to ride around at 7500 to 8000 at times.

[TheGreatWhite]

1 minute ago, dripley said:

I was wondering. It is not odd for me to ride around at 7500 to 8000 at times.

Yeah cause I asked my brother and he said we were 11k with a pretty heavy trailer and a ton on said trailer.

Edited December 28, 2019 by TheGreatWhite

[NIsaacs]

Flat bed dually's take power and fuel just to roll. My Ford only gets 16 mpg and it is a VE pumped 12 valve, way less power than yours. The flat bed is 8' wide, air horns, full size west coast mirrors, two transmissions and stacks all take a toll.

 

 

[Mopar1973Man]

Funny thing I just scaled my truck. Front was 4,400 pounds, the rear was 2,900 pounds, for a total of 7,300 pounds currently. Here is current fuel logs with winterized fuel and outside temps between 0*F and 25*F most days. Remember I went down in tire size to increase the rear ratio. Going from 265's to 245's change the final ratio to 3.69:1 which is super quick and extremely low in engine load at 22-25% at 80 MPH. My 65 MPH is rough 15-17% engine load. 

 

 

Edited December 28, 2019 by Mopar1973Man

[TheGreatWhite]

3 hours ago, NIsaacs said:

Flat bed dually's take power and fuel just to roll. My Ford only gets 16 mpg and it is a VE pumped 12 valve, way less power than yours. The flat bed is 8' wide, air horns, full size west coast mirrors, two transmissions and stacks all take a toll.

 

 

Man that is a beautiful truck! I've been looking for old Ford's in that body style or a 60-70s Power Wagon to put a Cummins in.

 

2 hours ago, Mopar1973Man said:

Funny thing I just scaled my truck. Front was 4,400 pounds, the rear was 2,900 pounds, for a total of 7,300 pounds currently. Here is current fuel logs with winterized fuel and outside temps between 0*F and 25*F most days. Remember I went down in tire size to increase the rear ratio. Going from 265's to 245's change the final ratio to 3.69:1 which is super quick and extremely low in engine load at 22-25% at 80 MPH. My 65 MPH is rough 15-17% engine load. 

 

 

I'm starting to concede to the whole smaller tire idea more and more but I don't get it, why do people keep saying to go with a bigger tire to drop the rear end down to get better mileage? My dad had a 95 that started out with 4.11s and fuel sucked, so he swapped them for 3.53s and from then on got 22mpg consistently on the same exact tires I run, 235/85/16, and even one time went to 285s and still got great mileage. 

[Mopar1973Man]

That green marker was 120 mile round trip to Boise running the interstate at 82 MPH @ 2500 RPMs. Just short at 19.92 MPG.

 

Remember for every 1 pound of rotational mass you can remove is like 8 pounds off the frame weight.

 

Oh 405k miles on the clock. Injectors are good still with 7 to 12% idle engine load. That 320 bar pop pressure really helps.

Edited December 28, 2019 by Mopar1973Man

[TheGreatWhite]

10 minutes ago, Mopar1973Man said:

That green marker was 120 mile round trip to Boise running the interstate at 82 MPH @ 2500 RPMs. Just short at 19.92 MPG.

 

Remember for every 1 pound of rotational mass you can remove is like 8 pounds off the frame weight.

 

Oh 405k miles on the clock. Injectors are good still with 7 to 12% idle engine load. That 320 bar pop pressure really helps.

Is that 7-12% at idle? At idle I'm 5-7%.

 

My injectors are just 7.009 DAP Bosch VCOs, do you know off hand what their pop pressure is?

[Mopar1973Man]

1 minute ago, TheGreatWhite said:

Is that 7-12% at idle? At idle I'm 5-7%.

 

My injectors are just 7.009 DAP Bosch VCOs, do you know off hand what their pop pressure is?

Start out typically at 305 or 300 bar. Bottom limit is 293 bar. By 260 bar engine load typically bottoms out 0 engine load.

 

Hence why I started at 320 bar for economy and longevity reasons. Upper limit from the Dodge FSM is 327 bar.

[TheGreatWhite]

4 minutes ago, Mopar1973Man said:

Start out typically at 305 or 300 bar. Bottom limit is 293 bar. By 260 bar engine load typically bottoms out 0 engine load.

 

Hence why I started at 320 bar for economy and longevity reasons. Upper limit from the Dodge FSM is 327 bar.

So to up the bar is that sending them back to DAP or can I take them to my nearest certified Bosch pump and injector shop? I have a good buddy who works there that can hook me up on some injector work.

[Mopar1973Man]

I would opt for 315 bar for those 7 x 0.009 injectors. Any shop can do pop testing.

[TheGreatWhite]

12 minutes ago, Mopar1973Man said:

I would opt for 315 bar for those 7 x 0.009 injectors. Any shop can do pop testing.

So here's a question and an idea, would a turbo do anything with lowering the load? I have a Smeding 62/65/14 I've been thinking about throwing on the ole girl, either that or I have a stock he351cw. Would either or help with engine load and mileage?