Teddy Bear

Ive got a friend with a 06 6spd 3500. He uses it quite a bit for haulin cattle. Usually pulls a 28ft. stoll. He really likes the truck and says it has plenty of power but he's really disappointed with his fuel mileage. He was asking me about maybe getting some kind of programmer to help his mileage out some. Hes only averaging about 9-10mpg with his truck. His previous 2nd gen got much better mileage. What kind of programmer/box do you guys reccomend for him? The truck is bone stock except for the exhaust. Are there any boxes out there that are untraceable by the dealer?? I really dont think he wants to shell out the $$$ for the smarty so thats out of the question. Thanks for any help guys

Speed Shift

TST has a new mileage only box. http://www.tstproducts.com It adds 50hp also, its just really built for mileage.

omaharam

Disclaimer - opinions are like....well you know the saying.

Here's my opinion...
How do you add power to a diesel? You add fuel. If you are adding 50hp, you are using more fuel. I don't believe that enyone has shown long term results for ANY box that has done much for mileage. Once he gets some miles on it, it will do a little better, but these new powerful trucks will never see the numbers that the 2nd gen guys get to experience. When I hit around 20k, my mileage seemed to get a little better. When I first got it, I was about 17-18 at 70mph. When I went to 315s it didn't seem to hurt the towing mileage too much and the unloaded highway mileage went up due to the drop in rpms. Now at 46k miles, I can get right at 20mpg undloaded at 70mph at 1800rpm. If I run it at 2krpm, it drops to like 17. I believe the two greatest benefits for mileage are getting enough miles on it to get things loosened up and keeping that tach below 2000prm. If he is one of those guys that likes to tow going 80mph, a larger diameter tire MIGHT help his mileage by keeping the rpms down.

Speed Shift

Man I am sorry but none of that is true.

HP in a diesel is not just fuel, mostley yes, but not all. Aftermarket boxes change two aspects of fuel delivery, and timming. Timming, Duration, and Pressure. Some boxes do all three, some do just one, some do two. EX. a TST Powermax CR box is timing and duration, unless it is the new box with pressure also, a Edge EZ is pressure only, a Smarty is duration only or duration and timing. I can go on and on, about all the different boxes there are. Injectors can give better milage by a more refined spray pattern, cams can give better milage by intake and exhuast valves being opened and closed to be more efficient. There are a lot more ways to make power in a diesel than just pouring fuel into it. The more effiecient an engine is the better milage it will get. DC has rules to build by, we can choose to change those.

Bigger tires will get you worse milage overall. Some have seen improved highway mpg because of a drop in rpms, but most decrease. This is the oldest most talked about topic on the forum. As far as towing with larger tires really expect a drop in milage because now the power you had to tow is all left higher in the rpm range, and it will lug and loose more miles per gallon.

These are facts.

wap

My tires didnt help my milage, but I cant say they hurt it either but I dont try too hard to get good milage. I used to put 2-3000 interstate miles a month at 80mph butI usually only drive my truck on the weekends now so when I get a chance to take her for a spin I have fun with it.

He may try the quad xzt, wich is a pressure box.

omaha, not arguin but on the comment about addin fuel, most "econemy" settins on adjustable boxes are timing only so it may not actually be addin more fuel.

mitternocht

There are lots of posts on here about fuel mileage, however everything seems to be against us these days. The dually doesn’t help, neither does ULSD or winter blend fuels. The G56 and the 3rd injection event in the 3rd gens are the biggest culprits in my opinion. You have to drive like pappy to keep the RPM’s down on the G56. The NV or the 48Re are geared higher so RPM’s stay a bit lower.

The cheapest thing to do is keep it serviced, use synthetic oils and keep the air pressure up especially in the front tires. Also fuel additives can help a bit.

omaharam

Pressure is more fuel. Duration is more fuel. Timing is not, I agree, but find me someone who has actually seen a documented increase in mileage due to a box.
As far as cams, injectors, etc, why aren't we all getting 25mph then? Do a search, there hasn't been anyone who has said, here is my set up and I am now getting 23mpg just like my buddie's '97. How much would a guy spend on these mods and how many miles would he have to drive to get his money back even if it did work?

As far as tires, I know what my truck did and does. A lot of guys that go to a larger tire are going to a mud terrain. That will hurt mileage. My truck gets better mileage on the interstate with the larger tires - fact - tried and true. As far as towing mileage - like I said, it didn't improve but it didn't hurt it either. When I'm going 70mph towing, as long as I'm not on a steep grade, it holds speed just fine in OD. The boost comes up and the rpms never move. I'm not saying that bigger tires WILL help mileage. If you look at my post, I capitalized "MIGHT". The particular tires I chose with my particular set up, has helped my unloaded highway mileage - period.

wap

mitter, I have never driven a NV5600 equipted truck but I would kinda think that the G56 should/might get better milage while towin especially a stock trailer that is 28' long.

What are your/yalls thoughts?

Speed Shift

OK, me

I got better mileage with my EZ box first and then I stacked a Smarty on it, with level 3(timing and duration) and it got even better as long as I stayed out of it. So there is Timing, pressure, and duration that all helped me get hand calculated mileage increases.

I am not comparing a CR to a 2nd gen, I know it wold not be logical to spend $5k on engine parts just for mileage, but they do help, and they do not add fuel, that was my point.

Here is a 10 second common rail that gets 24 MPG, with 750+ HP
I bet he has a "BOX" This is a post by Chris at Relentless Diesel.

Just thought some of you might like to know we have a new video in the media section of the website.

We finally broke into the 10's with a common rail powered Cummins.

See Video Here!

It was the first run of the night and we didn't have it fired up all the way.

60' time was only 1.84 on this pass. It's been about 2 tenths quicker in the past.

We were testing a new brake system out to help launch the truck harder. After the first pass the tech inspector told us to leave the track because the driver wasn't wearing a fire retarding jacket.

After some begging on our part they allowed us to run 1/8th miles as long as we didn't finish the 1/4 mile under 11.50.

On the third pass we attempted to launch the truck at full power and ripped the caliper mount off at the starting line. Back on the trailer, back to the chassis shop.

For what it's worth the truck dyno'd 759HP uncorrected on a dynojet dyno. We'll post video of that later, but you can hear the tires spinning on the rollers during the pull. We weren't prepared with extra weight to increase traction, so we just called it good.

HP calculators estimate the HP required to push 5440 lbs to 125 MPH in 1320 ft @ ~830HP rear wheel.

The truck runs a 3.55 rear gear and is RPM limited at 125 MPH.
You can watch the smoke stop before he reaches the finish line as the engine governor kicks in to put a halt to any more acceleration.

We originally built the truck to run 10.80 @ 125 while maintaining perfect street manners to drive daily on the street. We just didn't expect it to be so easy to make that kind of power.

We now have to decide to either re-gear the truck to run MORE MPH or just settle for high 10's and work on getting it to launch a little harder.

Either way we are all very excited about this and wanted to share this with all of you guys.

Some of you are probably wondering what kind of performance parts it takes to make this kind of power.

The truck started life as a 2003 Dodge regular cab long bed. The frame was clipped for the short bed. It runs a simple ladder bar setup with coil overs for the rear suspention. We chunked the AAM rear axle for something we were more familiar with. The new rear end contains a Dana 80 center section for strength and mossier axles w/ 5 bolt lug patterns to accomodate big wheels and slicks. They also changed out the front end components to accomodate 5 bolt lug patterns to be able to purchase matching wheels front and rear.

For airflow improvements it has our Arctic Air twin turbo kit feeding 58 psi of boost through the stock intercooler. A Helix 2 camshaft from Don @ F1 diesel tickles the valves and the exhaust leaves through dual 5" stacks.

The fuel system starts in the bed with a 20 gallon fuel cell. It has two carter fuel pumps each with separate fuel filters delivering a mere 12 psi to the engine.
We did our own CP3 modifications which we are not discussing at this time.
It has custom injectors along with a TST PowerMax and an Edge EZ for electronic manipulation.

It runs a fully automatic DTT transmission we built in house. No rachet shifter here just put it in 'D', mash the loud pedal and hold on.

The truck still has all factory options such as air conditioning, stereo, electric windows and door locks. It's a blast to drive. Imagine cruising at 80MPH and having the ability to stomp the loud pedal and send the tires up in smoke.

If you can keep your foot out of it (not likely) it gets over 24 MPG down the freeway.


I'll wrap up now. I thought some of you might be interested. Enjoy!

wap

SPEEDSHIFT, what kind of mpg are you gettin?

Speed Shift

17mpg hand calculated all city driving, my poor truck never sees 60mph

ramtd02

who told you this?? pressure just helps with better atomization for the fuel, allowing it too burn faster and more completely, in no way does adding pressure increase the amount of fuel actually injected. It allows for more fuel too be injected due to more efficient combustion, but it does not necessarily mean that more fuel is actually used!

morkable

you are absolutely correct ram. Diesel engines work alot different than what we have come to learn from gasoline engines. Our trucks personify the meaning of efficiency (sp). Not only do we get more HP, but also better fuel mileage when we increase performance. My truck for example has gone as far as 1400km to 1 tank of fuel, and as low as 850km. (The difference seems to be in the fuel station used.) I average around 20MPG around town. (which you have to remember I can go farther on a gallon because we go on an imperial gallon here in canada).

Kevin

oh yeah,, and I think for your friend I would personally recommend either one of the quad boxes like the xzt or a bullydog power pup. The edge ez also works good in those types of situations too

gsbrockman

If an EDGE EZ (pressure only programmer) only "better atomizes" the fuel, then please explain to me the HP increases on a dyno. Extra fuel flow has to be there to increase the HP figures. I ran an EZ and it would more quickly drop my fuel pressure gauge than the Juice w/Attitude I now run.

An increase in rail pressure does indeed allow for extra fuel to be injected. That's why power-hungry guys run a pressure box stacked with their favorite timing & duration boxes on a HPCR---thus more HP.

If you turn your faucet on to your water hose 1/3 of a turn and hold the "trigger" for 5 seconds and squirt into a bucket, you'll get xx ozs. of water. Try cranking the faucet all the way open, pull the "trigger" and squirt for 5 seconds, and I'm sure you'll get more water.

Greg

mitternocht

Well, it might depend on how fast you try to go. I managed 16 MPG at around 65 MPH with a loaded single car trailer in tow. The 3rd injection event on the newer trucks doesn’t do anything for MPG, this is one of the reasons the why the older models do better.

MPG with respect to towing at different RPMs is a function of how efficient the engine is at the different RPMs. Lowering the RPMs just means more torque is required which requires more fuel and air per combustion cycle even though you have less cycles. Higher RPMs just mean less fuel and air per cycle, but more cycles. For a given load there is always an ideal RPM to be at for maximum fuel efficiency, however in the real world is very difficult to keep the engine at that RPM even if you know where it was.