bluesfan1961
Eastern Shore, MD
Full Member
Joined: 12/23/2007
View Profile
 Offline
|
Towing a 10,000# with an F250 PSD mostly downhill (we live on the flats) we avg 12-13 mpg. Towing nada we avg 17mpg.
|
robwen
NE OH
New Member
Joined: 03/01/2005
View Profile
|
'99 7.3 automatic towing a a '98 30' TT i get between 9-11 depending on speed, gear used, and wind. truck gets mid teens empty. truck gets low mpg in general for a PSD.
'86 6.9 IDI gets 10-12 towing and mid teens empty with a C6 auto trans. but it's cheap to fix and more tolerant of alternative fuels.
'98 Sunnybrook 30DB
'86 F350 CC 4x4 6.9L
'99 F250 SC 4x4 7.3L
|
Terryallan
NC
Senior Member
Joined: 06/28/2004
View Profile
Offline
|
phyllen wrote:Strangest thing. A few years ago we had a 1989 30' Georgie Boy MH. We left NJ and went to Louisiana and back. Going through the mountains and hills in Virginia and Tennessee we got about 5.5 MPG. We hit flat land in Mississippi and Louisiana and it dropped to 4.5. We could not understand it!
Last October we took the same trip but with our F250 superduty Diesel pulling a 36' Cedar Creek Fifth Wheel. Through the mountains we were getting a little 9 mpg. We hit the flat land in it dropped to 8.5 or less.
Anyone have an explanation?
Some vehicles just like the mountains. Our Expe did. The higher up the better it ran.
Also. In the mountains. You are usually going slower than on the flats, and 1/2 of it is down hill.
Terry & Shay
Pioneer 23T6
04 F150, 5.4, Lariat SuperCab
Lazy Campers
NC
|
Rubiranch
Salt Lake City, UT
Senior Member
Joined: 03/09/2004
View Profile
|
Several of us took a trip a month or so ago;
We got 8.6 mpg round trip.
Our friend with a 97 7.3L PSD pulling a 27' TT averages about 10.
03 Dodge Hemi towing a 20' Puma abot 8.
96 F-250 towing a light 24' with a 5.8L got about 8.
TV: Mint 1972 Ford F-250 XLT
TT: 1969 19' Excel; entertains 6, feeds 4, sleeps 2
You don't shoot to kill, you shoot to stay alive.
I don't carry because I have to, I carry because I get to.
I like new things-
- when they're 40 years old!
My pictures
|
cybervanner
Richmond, VA
Senior Member
Joined: 09/25/2007
View Profile
Offline
|
Higher elevations mean less air pressure. Most modern engines have what is called a MAP sensor, or Manifold Air Pressure sensor. The MAP sensor reads actual air pressure of the air between the throttle and the engine's combustion chamber. The ECM uses this information to tell how much air the engine is drawing in, and thus meters the approperiate amount of fuel necessary for optimal performance. The MAP sensor doesn't read the difference in air pressure between outside the engine and inside the engine, it actually uses ZERO air pressure as it's reference point instead, making it reactive to the thinner air at higher altitudes.
In other words, with the throttle closed, to the MAP sensor, you don't have high vacuum, but low air pressure (remember, you can never have a complete vacuum). If the barometric air pressure starts off lower like when you are driving high up in the mountains, the MAP sensor, even at full throttle reads that there's less air entering the engine than it would be at "sea level", thus, the ECM meters out less fuel! Since you were driving in the mountains, I imagine a considerable period of your trip was in high altitudes.
|
|
|
TRAILER TRASH
On The Road
New Member
Joined: 10/20/2007
View Profile
Offline
|
With an '06 2500 Sliverado and 6,000 lb trailer I get a steady 14mpg, but only if I keep the speed below 60mph. Faster than that the mpg falls to less than 10mpg. If you want to save fuel... SLOW DOWN !!!
NY FOLK, GOOFIN ALONG
|
DadToFourBoys
Texas
Senior Member
Joined: 04/09/2007
View Profile
Offline
|
I get 10-11 at 60mph with my 1/2 ton 2004 Burb towing our 31' trailer. This is mostly in the Texas Hill Country and on flats.
|
Rubiranch
Salt Lake City, UT
Senior Member
Joined: 03/09/2004
View Profile
|
cybervanner wrote:(remember, you can never have a complete vacuum)
There is no "vacuum" here on earth, just negative pressure.
If your vehicle has a MAF (mass air flow sensor) then altitude is calculated at WOT.
With a vehicle equipped with a MAF it is possible to travel fromm sea level to 10,000 ft and if you never reach WOT (wide open throttle) the vehicle may just think you're still at seal level.
|
Catfishman
North Texas
Full Member
Joined: 08/13/2004
View Profile
|
Ours is amazingly consistent! We get 10 mpg anywhere we go in the state of Texas. I used to have the DW pull out the calculator. Not anymore. When I travel 240 miles, the next fuel stop will require 24 gallons. I guess I'm living the simplified retirement I always dreamed about! 
2003 GMC Sierra 1500
5.3L - 3.73 Ratio
2002 Coachmen 249QB
If you can't fix it with a hammer, you've got an electrical problem!
|
canoe on top
Denver, CO, US
Senior Member
Joined: 07/21/2003
View Profile
Offline
|
'06 CTD 5500lb Nash. 12-14mpg. 14 if I stay around 1800 rpm or less which is about 60mph. 15-17 around town empty and high teens/low twentys solo highway. 24.7 recently empty and cruising around 60mph. 18-19 at 75mph solo.
|
|
|
