Low fuel mileage on Semi Trucks

Heh. My '91 FL Cabover car hauler got around 3.5-4.0 empty or loaded.

 

2016 Freightliner currently running 8.8 mpg pulling 30k up towards Conklin, NY. Seen some mountains, seen some flatlands, been on a couple goat paths and ran some 4 lane interstate... honestly surprised I'm not sub-7 at this point, though, given how much I've idled this trip

 

Our average with the 2001 Century used as a team that year would fall in the region of 6.8 miles to gallon. Alot depends on what you are doing, or not doing to it. If you are say eastbound into Kansas from Limon CO during summer storms that catch up to you and then pass in few hours pushing your trailer like a sailboat, your mileage approach 20 miles to gallon loaded. For only a limited time.

Once in a while when I am aware the fuel is really low, my driving changes to that of having a eggshell under that right foot and only using just enough RPM to keep the engine turning over rolling down the highway on georgia overdrive as much as possible. Ive seen my FLD 120 get upwards of 7 mpg in these conditions. That's good for about 2100 miles on 300 gallons of fuel with the last 24 in reserve.

Most old iron it's either 5 mpg give or take one or gallons per hour against a mountain up and over.

The more horse you have on hand the less work you do to lift it up and over, gives you better mileage.

 

Um ouch. That number is with me hauling 45 to 48000 lb every load and all my loads go up and down Interstate 5 so lots of Rolling Hills and passes.

 

I have the International with A26. I give them a plug wherever I can. I’m very pleased with it. I get .17 less than this number or 9.29 mpg. Reefer freight, 72k average gross, lots of Northeast running.

 

All these great #s, if going by a computer on the dash, can’t be trusted. Checking gallons replaced vs miles ran, and averaged out over multiple tanks is more accurate. The last Truck I had with the computer read out, lied progressively. The higher the # on computer, the wider the gap in reality.

 

The only real way to check mileage has been used since the first combustion engine was put in something with wheels, waaaaaay before a computer was dreamed up. lol

 

I’m the last person to tell anyone how to get MPGs. I’ve gotten as high as 6,5, last trip was 4.8. Idled 3 days on a 1000 mile trip. I was sorry I checked it. Lol

 

And what of an external computer, such as a Qualcomm?

 

Your Qualcomm reads info from the ecm, so you'd have the same false info. The only accurate way to check is by pencil and paper. Or a calculator.