Montana Owners Club - Keystone Montana 5th Wheel Forum - View Single Post

sreigle · 04-20-2006, 12:45 PM

Steve, your mileage will get better with more miles on the truck, if my experience is any indication. Ours has 51,000 on it now (2005 F250 6.0L 3.73 TorqShift CrewCab). Until recently (see below) our mileage had peaked at 17 to 21 at highway speeds (over 72 drops the mileage). Town is 15 to 17 depending on how much is city freeway and how much is stoplight stop and go. 16.x was most common. Towing we averaged about 11.5 with lows around 9 in extreme mountainous conditions to 14 in flatlands with a tailwind. The Montana weighs 14,360 and total rig is 22,920 (both within the truck's specs).

Last week we towed Utah highway 24 from Hanksville to Torrey, then Utah 12 from Torrey to Cannonville, near Bryce Canyon. I knew this would be a beautiful drive but nobody warned me about the grades. I now know this F250 powerstroke will tow all 14,360 pounds of Montana up (and down the other side also at 14%) a 14% grade of roughly two miles duration. This road has several 8 percenters, a couple of 10 percenters, one 12 percenter and one 14 percenter. Speed limit on the 14 percenter and the 12 percenter was 35 with curves at lower recommended speeds. We held the speed limit with plenty of throttle remaining. I would not have run a higher speed because EGT (pre-turbo) wanted to go over 1200 when I tried. I backed down to 35 to keep EGT closer to 1100.

I also am even more convinced, after going down that 14 percenter that between the TorqShift smart downshifting (in tow/haul) and the exhaust backpressure from the turbo vanes closing that I do not need an exhaust brake in this truck.

I got off the mileage a bit. That stretch I described was only about 150 miles but we got 9.3 on that stretch. We had some serious elevation changes on this stretch but, wow, what a gorgeous drive.

After all that, I think our mileage has dropped from what it was. We had the recall done while in the Rio Grande Valley, the one that replaces the exhaust gas pressure sensor. At that time they flashed the engine computer with the latest updates. We have put about 4,500 miles on the truck since then and I am convinced mileage is down between 1 and 2 mpg in all modes - city, highway, solo, towing.

04-20-2006, 12:45 PM	#14
sreigle Montana Master Join Date: Nov 2002 Location: Oceanside Posts: 20,028 M.O.C. #20	Steve, your mileage will get better with more miles on the truck, if my experience is any indication. Ours has 51,000 on it now (2005 F250 6.0L 3.73 TorqShift CrewCab). Until recently (see below) our mileage had peaked at 17 to 21 at highway speeds (over 72 drops the mileage). Town is 15 to 17 depending on how much is city freeway and how much is stoplight stop and go. 16.x was most common. Towing we averaged about 11.5 with lows around 9 in extreme mountainous conditions to 14 in flatlands with a tailwind. The Montana weighs 14,360 and total rig is 22,920 (both within the truck's specs). Last week we towed Utah highway 24 from Hanksville to Torrey, then Utah 12 from Torrey to Cannonville, near Bryce Canyon. I knew this would be a beautiful drive but nobody warned me about the grades. I now know this F250 powerstroke will tow all 14,360 pounds of Montana up (and down the other side also at 14%) a 14% grade of roughly two miles duration. This road has several 8 percenters, a couple of 10 percenters, one 12 percenter and one 14 percenter. Speed limit on the 14 percenter and the 12 percenter was 35 with curves at lower recommended speeds. We held the speed limit with plenty of throttle remaining. I would not have run a higher speed because EGT (pre-turbo) wanted to go over 1200 when I tried. I backed down to 35 to keep EGT closer to 1100. I also am even more convinced, after going down that 14 percenter that between the TorqShift smart downshifting (in tow/haul) and the exhaust backpressure from the turbo vanes closing that I do not need an exhaust brake in this truck. I got off the mileage a bit. That stretch I described was only about 150 miles but we got 9.3 on that stretch. We had some serious elevation changes on this stretch but, wow, what a gorgeous drive. After all that, I think our mileage has dropped from what it was. We had the recall done while in the Rio Grande Valley, the one that replaces the exhaust gas pressure sensor. At that time they flashed the engine computer with the latest updates. We have put about 4,500 miles on the truck since then and I am convinced mileage is down between 1 and 2 mpg in all modes - city, highway, solo, towing.