crlnmry

Hi

I spoke to the Dodge reps at our state fair in Dallas TX.

Asked if they had any suggestions to increase the fuel
mileage for my 05 2wd Cummings.

Both Dodge factory reps said the only thing to do is keep the air filter clean. Claimed that the chip was updated in late 04 for better ecconomy.

Does anyone have any solutions to increase the milage?

My milage stays around 20-21 as much of my driving is on the road.

I found that mobil one did nothing to impove the milage and is very expensive.

With diesel at 2.50 compared to gas its a huge rip.

The Dodge reps did say that in 07 Dodge was working on increasing the fuel ecconomy.

Andy505

it's spelled cummins, there is no "g"

donhov

Guess I would have to ask where else can you drive a 3 1/2 ton truck either auto or manual and get 21 MPG. I agree that diesel pricing is a rip this year but still my gasser 1500 only got 14 empty at 70MPH. and no power like the Cummins. Put a chip in it, keep your foot out of it and drive under 2000 RPm and keep under 70 MPH, maybe you can squeek a few more MPG out of it.

JM02

12PACK

This question comes up often and this seems to be the most common answer. Keeping the rpm's under 2K seems to be the easiest thing to do.

BigBlue

Why are you complaining if your getting 20-21mpg? I only get that kind of mileage if I stay at 72mph, keep the boost under 10psi, run a fuel cleaner, and don't eat for 12 hours.

bigblock2stroke

He is clueless on the last comment. More emissions standards in 07 is not going to improve the fuel economy.

Here's my proposed list

1.)Advance the injection timing through either the Rokktech crank sensor or SuperDuty's tonewheel modification. Both can be found by doing a search in this forum.

2.) Keep the tires inflated to the max or the maximum your butt can handle (the ride will get rougher as you add air to the tires).

3.) Keeping rpm's below 2000 usually requires larger tires. Try not to go wider, just taller. The point being to numerically lower your final drive ratio.

4.) When driving, let the vehicle coast as far as you can. When you see the light up ahead is going to change to red, let off the pedal and coast as far as you can. This will also save your brakes some. Also try timing the lights, as the stop/go (conserving momentum) takes alot of fuel.

5.) Accelerate slowly, because boost is what takes the most fuel. The more boost you have the more fuel will be added to sustain combustion. These are diesel trucks made for towing, not race cars (I'm sure I'll be chastized for that, but whatever). If you want to race stop light to stop light, buy a Charger SRT-8.

6.) Don't let the truck idle unnecessarily.

7.) Keep your air filter and fuel filter clean (but I don't think it does as much for you as the above).

Superduty

8) buy a 2WD.

9) DON'T PUT BIG TIRES ON THE TRUCK. Big tires have lots of rolling resistance, especially if they are run at low air pressures.

10) Don't lift the truck. Higher = more wind resistance.

11) Get a 6 speed and short shift it.

bluebull

I was depressed about the price of fuel for a while too until I got out the calculator and done some syphering.
If my diesel truck gets 18 MPG and a gasser truck gets 15 MPG the price difference can be 45 cents per gallon higher for diesel than gas. If diesel is less than 45 cents difference than gas I am saving money.

Your truck gets alot better fuel milage than mine so the difference in price of diesel and gas would be alot higher, so you are saving big money over a gas truck. If you don't need a gas or diesel truck than buy a small used car, that's the only way I know of how to increase fuel milage, of course for what you pay for the small car would buy you alot of extra diesel on top of what you would spend anyhow for driving the miles you need to drive anyhow.

bigblock2stroke

a little bigger should help, more so on the highway.

2wd is in fact better but I love 4wd in the snow/mud with all the weight up front the 2wd's get stuck easy.

The G56 is actually worse than the auto for fuel economy.

I had the chance to drive a 4.10 with G56. 70mph at around 2500rpm.

Some accountant's definitely have their heads up their Edit on this one. That is why I have been telling everyone to go complain about poor fuel economy. I have complained to my dealer and I'm getting around 18mpg. It can only help if everyone puts in a complaint.

bluebull

I didn't think you could get a G56 with the 4:10's, only the auto's could be ordered with 4:10's???

motrapper

wrong ido

SolarExpress

I'm thinking a 3.54 diff would help greatly in the mileage. At 70mph with the G56, 'm turning 2,250 rpm. To high in my opinion, but who am I? Turning 1700-1800 in 6th gear this thing has TONS of get up and go left. I would love to be in that range at 65-70 mph. I'm REALLY complaining about the mileage, I get 19-21 depending on my foot and traffic levels, but a couple of extra mileage points would be great. My solution (wish list) is 3.54's and an increase of about 1" on tire diameter.

Superduty

"<tires>:a little bigger should help, more so on the highway."

Taller tires do decrease the effective effective gear ratio and that is a good thing. But, there are bigger tires and then there are bigger tires. A lot of the bigger than stock tires people put on are wider, which increases rolling resistance and they are a softer compound, more aggressive tread and they get run at lower air pressure. All of this is bad.

Then people lift the truck which is bad for aerodynamics because a) it increases the wind envelope. b) much more wind starts going under the truck, where it isn't streamlined. c) they put fender flares on and tires stick out the side of the truck. Throw a winch on for good measure, maybe a light bar and mileage goes way down.

Consider this: 1HP is less than 6 pounds of resistance at 70 MPH (1HP = 550ftlbs/sec. 70MPH is 102 ft/sec. 550/102 = 5.5 lbs.) Put your hand out the window and you've created 1HP of drag. Lift your truck, but on big soft tires. Put on extra lights, a big grill and a winch. All of a sudden your truck takes another 10 or 20HP to roll down the road.

"The G56 is actually worse than the auto for fuel economy." I don't understand the OD gearing on the G56 either.

" I had the chance to drive a 4.10 with G56. 70mph at around 2500rpm."

That ain't nothing compared to an F450SD with the 4.88 rear axle. There should be laws against doing something so stupid as building a truck like that.

rammtuff

You must remember that you paid a hefty premium for that oil burning block of steel under your hood. If gas=diesel (by way of fuel economy calculations) then the ol Cummins never gets paid off.
Gasser engines these days last 200-300k no prob.

Journier

true gas engines do last a long time. i dont know about 200-300,000 but id definately say 150,000 is acheivable on a majority.

cummins is built for work, thats why i couldnt tow 7,000 pounds with a gas truck against a wind and keep it above 55 :/

not sure if im ahead or not with buying a cummins powered ram, and getting like 16 mpg with 7k pounds behind me :/ where my 360 mopar gasser was at like 8mpg or less.