Better fuel mileage with a Dodge/Cummins truck

[Doubletrouble]

 I though i would post up what I know about better fuel mileage thus far. Gearing and tire size have a lot to do with it as well as driving habits. there are many variables. My truck is a mainly stock 2nd gen 3500 dually with a 5 speed manual so I will speak to this truck in the post. others can add their tips pertaining to their setup as we go. I know some of you have tuners that make a huge difference but not all do. the Quadzilla adrenaline seems to be the go to for mileage and power among other things. That being said, here are some basic tips to get a bit more MPG's

 

 !. A well maintained engine. 

Change oil, a clean engine is more efficient, good fresh oil helps 

check your air filter minder, change filter if needed

How many miles on your injectors? (see article in tech section to determine their condition)

Low Pop Pressure and detecting it - Fuel - Mopar1973Man's Dodge Cummins Forum

 

2. Tire pressure.

we should all know by now that a flat or low tire doesn't roll as well as a fully inflated one. Check your pressure!

I don't really recommend over inflating your tires since it will cause uneven wear, lower the contact area to the road and ride rougher as well but in my experience a few extra lbs of pressure don't hurt. Do not go over the pressure on the sidewall of the tire! My sticker from the factory states 65lbs/front and 50lbs/rear. Tire sidewall says 80psi max. I normally run what the sticker states because I don't haul all the time. Most of my miles are an empty truck. That being said I still wear the center of the rear tires since there is not enough weight back there to flatten the contact area to the pavement. 

While we are on tires, alignment is important as well, have it checked or check it yourself. it can be done. Also check for worn suspension parts at this time. You wont get good results with worn out parts in place.

Oversize tires, well you kinda knew your mileage would fall off didn't you? There are ways to get some back but I wont go into that here. I am using my truck and experiences with it. Someone else may chime in.

 

3. Drum brake guys.

Make sure you keep your rear drums adjusted properly but try not to allow them to drag when the brakes are not applied. This will create a parasitic drag on your drive train. Like pulling a small trailer. It will lower you MPG's

 

4. Do you really need all that stuff in your truck?

Reduce the weight! I have a tool box behind the cab, i carry jumper cables, straps, a chain and a few other things. I have used all the items I carry at one point so I leave them in there. I do not carry an entire tool set with me as it's not needed. Any extra weight you can leave at home will help.

 

5. Winter fuel

Winter fuel will not yield the same MPG's as summer fuel. I live in Northern Ohio so we do get winter blended fuel when the temps drop. I do notice a difference. There is more of that ex[plained on this site, maybe someone could post a link for me? Thanks

 

6. Driving habits

If you are one to go full throttle from stoplight to stoplight then well, that's not gonna help your mileage. I have a 5 speed manual and usually drive pretty conservatively. I shift gears at around 2000-2200 RPM. I don't try to drive my truck like a race car. I average 17.5 MPG just daily driving. Prior to this truck I owned a 1999 Chevy suburban that only got 16 MPG doing the same thing. Now i have twice the truck (if not more) with better MPG's. Drive conservatively and you will save a little at the pump.

 

 I thought I would put this up with the fuel prices getting out of control in most places. Some will be looking to find ways to save a few $$ here and there. If anyone else has something they would like to add or if I missed or forget something please feel free to toss it in here. I feel most of my suggestions are basic but sometimes get overlooked.

 

 

[Max Tune]

I agree with everything you posted. Most of it falls under basic maintenance, which can get away from you without even realizing it.

 

I own two duallies. My '02 Dodge and my FILs '04 Ford. Last thing I worry about is milage. I check it every fill up, but that's just to watch for any big changes to catch a problem. Every vehicle I've owned, from Geo Metros to these duallies and everything in between, I just drive and the milage I get is the milage I get.

 

That's just me......

[Doubletrouble]

 @Max Tune I agree, I didn't buy a dually for fuel mileage. With fuel prices now days I thought I would post up some basics to get started. There may be some out there that are a little short due to economy that need to save a few dollars and cents where they can. I've been there myself in the past. 

[Max Tune]

Oh I definitely get it. My best way to get the most time, notice I didn't say milage, from a tank was to drive less. If you increase your milage +1 from normal, your only getting 15, 20, 30 miles more per tankful depending on how much fuel it takes to fill back up. Not a big game changer to me. It's like some of my friends that drive 10 miles away to save 5¢ a gallon. If they buy 20 gallons, they saved $1. Even if their car gets 20 mpg, it cost them over $3 to save $1. I'm all for better milage, but there is a limit to the time and effort I'm willing to invest to maximize my mpg. I don't fault anyone who is more willing to extract every bit of milage from their vehicle than I am, to each their own. That said, I will keep my vehicles maintained the best I can so they get the best mileage for how I drive and also last as long as possible. I generally keep a vehicle until it's ready for the boneyard.....

[Dieselfuture]

I got a VW TDI that I get at least 45 mpg so I drive that when I can, when I need the truck I use it and most times in summer I get 18 average, if I drive 60 I get over 20 but I don't have patience to do that. Some say having 2 vehicles is expensive I say not. To each their own. Not bashing anyone just my 

[wil440]

I have a Volvo 2020 XC40 hybrid thing, great car but souless, my wife drives it, range is 24 or so miles on electric but much lower this time of year due to running heater,seat heaters and stuff which is all on battery if it's charged, my wife never does more than 10mile per day so it is almost always on electricity, MPG display I think cannot go over 150mpg which is what it is always at, we have had it 3 months and the main dealer we got it from filled it with petrol before we drove it away, still on 1/2 tank and that is down to me as we are now on this E10 I think and they say it goes off faster so I when I drive it I make sure it uses petrol, 1500cc 3 cylinder petrol turbo 160hp and a 80hp electric motor, if you stomp it both run and boy does it go. 

I hate it but have to admit it is a good car.

I drive my ram 99.9% of the time, diesel here is £1.50 ish per litre so £6.75 a UK gallon which is just over $9, our pumps stop pumping at £100 which doesn't fill it from a line below 1/2

I need to get a set of injectors asap as my load at idle is low and MPG is low but it is mostly always towing, I just fill it and drive even at £1.50 per litre and yes I do have bigger wheels and tyres but they are not coming off, I'd put up with 5mpg 

[Sycostang67]

I'll have to wait until spring to see if I've gained any real mpg.  I have the adrenaline and smaller tires now but since I'm a big ol' weenie with my remote start my truck idles a lot in the winter.  I do love using the 3cyl high idle at work though, everyone in the building knows I'm getting ready to leave.  

[Doubletrouble]

13 minutes ago, Sycostang67 said:

I'll have to wait until spring to see if I've gained any real mpg.  I have the adrenaline and smaller tires now but since I'm a big ol' weenie with my remote start my truck idles a lot in the winter.  I do love using the 3cyl high idle at work though, everyone in the building knows I'm getting ready to leave.  

 I don't have the high idle feature on my truck. I talked to a local dealership, they told me about $60 to install or enable the factory programming. I didn't do it at the time because it was last spring and warm. I wouldn't have known if it worked until now. Lol

[Mopar1973Man]

The other way is to get your hands on a Smarty S-03 programmer and then flash one tune to the truck and then return to stock and your done. The high idle software is left on as a freeble. 

 

https://www.dieselautopower.com/smarty-s-03-rental-sr-s03a

 

As from DAP's site...

Quote

For those that want to install the newer software to enable high idle or test/tune with smarty programmer. Unit may be open box. Return is required in 21 days from shipment.  $50 fee assessed for shipping, return shipping and handling.  Will ship and return ship using USPS or UPS. Labels will be pre-paid. If not received in 21 days or sooner a $50 late fee will be assessed per week. Available to United States only. Call us, 1(801) 927-4600, for international options.

 

Edited December 30, 2021 by Mopar1973Man

[Doubletrouble]

1 hour ago, Mopar1973Man said:

The other way is to get your hands on a Smarty S-03 programmer and then flash one tune to the truck and then return to stock and your done. The high idle software is left on as a freeble. 

 

https://www.dieselautopower.com/smarty-s-03-rental-sr-s03a

 

As from DAP's site...

 

  I saw that on their site. How does that work? They show a price of $600 (if I remember correctly, could be wrong) but it states a fee of $50 for shipping to and from. I guess I don't understand how much it really costs..... 

 Don't know of anyone close to me that has one to "borrow" to get it done.

[Mopar1973Man]

All I can say is give DAP a call after the holidays and see with the gang there has to say. 

[Doubletrouble]

6 minutes ago, Mopar1973Man said:

All I can say is give DAP a call after the holidays and see with the gang there has to say. 

 Gonna be calling them anyway. I returned the radiator I ordered from Amazon ( sent the wrong one). Gonna order one from DAP this time. Don't know why I didn't use them in the first place. Brain cramp

[Silverwolf2691]

I seem to remember something about smarty removing the anti stall in standard trans trucks. That was some years ago now though.. Don't know if smarty fixed that. 

 

Anti stall is, if I recall, Cummins' way of helping people not stall the truck with a load, it automatically adds fuel if the throttle is still at 0 to keep things moving. It's the puff of black smoke out the exhaust if you take your foot off the clutch just a bit too fast combined with the sudden lurch forward. If there is any throttle input though, anti stall is shut off and you are on your own with the fueling.  

 

I think it works like the rental tools at advance. They are loaner tools, but you are actually buying them and returning them. Their way of covering the "I'm just gonna keep this, its really handy" people.

[Stanley]

Still trying to figure out my tuning problems...., everything else is up to par, however I am sitting at 11/12mpg 

Got work to do I'd suppose.

[Mopar1973Man]

How advanced is your timing?