Fuel Mileage Per Gallon

Yes, when they are empty. But the shape and airflow of a flatbed changes with a load, so it's never the same, and often a crapshoot. And depending on where the load is placed on a flatbed, you can have a big air gap between the tractor and the load, and that allows the air to fall out and cause turbulence.

At least with a van or a tank, the aero part remains the same empty or loaded. it's just the rolling resistance (weight) that changes on them.

 

The last truck I drove was a 2001 Freightliner Century Class with an "automatic" trans. I pulled a 2003 or 2004 Great Dane Air Ride 53' trailer.
I averaged 6.5 mpg with times of 7+ of course depending upon weight, terrain and load mileage. Weather has a definitive effect as well.
ONCE I got 9.3 mpg in New Mexico going west on I-10 with about a 10k# load. It was weird rolling at 55 in a 75 zone, but with that mpg it was worth it. JB, Swift and Roadway were passing me, so what.
It got pretty much the same mpg whether or not doing the speed limits.
It was fun yet I really prefer manual trannies. Mpg averages about the same what with idle time and all when the weather is too hot or too cool.

 

I drive a '98 Pete 379exhd with following specs:

3406b Cat 425hp (modded to 500HP) w/ 3:70 rear end and Im averaging about 5.7-6.5mpg

Being a cost concious O/O ive been toying with the idea of going aerodynamic (Pete 385/386 or Mack Vision -NO Freightshakers for me!) but giving up the classic feel of a 379 is not an easy feat...

 

I have really only driven two trucks.
A Penske Lease with 430hp/10spd got about 7-8 mpg.
An older freightliner daycab 3 axle with 350cat/8speed just did 480miles on 56 gallons cruising 65mph.
If we can get trucks to get 10mpg we'd all be making money.

 

I have added a fuel preporator, PF 200, and it got me just about 3/4 and a propane injection system, which gets me around 2mpg, so at times with the upgraded CAT, I am seeing a little over 8!!! up from around 5.5 to sometimes 6.
I spent about 950 on the fuel preporator and in total close to 3100 on the propane system. So in a little over 20k miles, they are gonna pay for themselves and then put $$$ in my pocket. I heard a guy call in to an XM show raving about getting 5mpg out of the same system, but I dont recall what type rig he was driving. It seems to be working for me.:smt001

 

I am running a 98 freightliner condo,500 hp detoit 60 series,super 10 speed,use cruise alot,run me. to wi.,get 6.75,gross 79000-80000,run over hwy 80,65-75mph. not too bad, no auxillary heater or air,get 6.56 when I let it idle 10 hrs.

 

diesel mpg went up 2 with propane but how much propane are you using?

 

2006 Freightliner Columbia (135,000 miles on it), 475 Detroit, 10 speed (not sure of the rears) usually 75,000-79,500

70% I-70 to e/w to and from cali
5% I-10 to e/w to and from cali
5% I-80 to e/w to and from cali
20% random roads moving where ever to grab a load to head back west.


I average 5.2 including 8-10 hours idle a day. cut out Idle I may average 5.5...

How and the heck you guys get 6.5 including idle and running the speed limit (that means running the speed limit, when it says 75 i'm going 75)
Is beyond me. Please enlighten me so I can apply this unknown knowledge to my truck driving.