I recently traded in my Ford F-150 5.4L V8 for a 2005 Dodge Ram 2500 with the Cummins Diesel engine, to tow my Tailgator motorcycle trailer, I was getting 5mpg with the gas truck, so I figured it was time to upgrade. Dry the trailer weighs about 6,000lbs and I generally do not run with the 100 gallon water tank. So figure another 2,000 tops for two motorcycles gear, gas etc.

I have a stock motor and 4:10 gear ratio. The home track is 250 miles away and all the other tracks are much further away. The truck has 4,000 miles on it and I found last week that driving at 65 mph I can get about 9ish mpg. However, many of the speedlimits on the way are 70 mph and it seems as soon as I move to 75mph my mpg drops down to between 6-7.5mpg.

I did a few searches and didn't find exactly what I was looking for. If I'm driving 75 mph lets say, would I be better off with a 3:75 or 3:55 gearing?

Also what would be minimum upgrades to help with this problem? Would a quadzilla box or edge ez help me with this?

I know the truck is new so I have some miles before it breaks in, I know I can drive slower to help with the problem but i was hoping a few of you guys in the know could help out a newbie, figure out what I can do to help my MPG at 75mph?

Thanks
Dave Z

 

First of all

Welcome to DTR.. Your mileage seems lower, but these trucks will get better mileage as they break in a little better. After all, it is a cummins adn it is designed for many many many miles. If top end speed is what you want, then you need some 3.73 or lower gear ratios, those 4.10s are over kill for what you are going to tow and at 60 mph (with my experience at least) i was already at 2000 rpms, anything over that with 4.10s will kill your mileage.

Fueling boxes, i know nothing about except, they do what they say, add more fuel. Which i would assume means less pedal pressure to get them to move. The only thing that box will do is void your warranty if its detected, But they will help with extra power and torque.

I would have gotten the lowest possible ratio for your truck for high speed highway driving, IMHO 410s are too extreme for that line of work, the cummins will also shrug off 6000 lbs like it isnt even back there as well..

tx

 

Most likely, you need to change your driving style. Reset your overhead display for mileage and keep trying to keep the average up there. This is probably the quickest way to see what influences the mileage you are seeing.

 

4.10s and driving fast will not yield good mileage. What size tires? Auto or manual tranny? Fill in your sig when you get a chance so we know what you are driving.