Notices

Trailering MPG??

Old 05-11-2008, 01:52 PM
  #1  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Dec 2007
Location: PBG, FL
Posts: 8,933
Default Trailering MPG??

I have a 2008 F 350 Diesel Long Bed Crew cab. Running 65 mph on the highway with no load i can get 21 mpg. Running 65 mph with 2000lbs in the bed i can still get around 19 or 20 mpg. However dragging my 21ft boat i get around 12mpg. I know it has more drag and the whole package probably weighs in between 5 and 6k but what is anyone else seeing when trailering?? Does a heavier boat change the efficiency as much as the aerodynamics? Just curious.
bradv is offline  
Old 05-11-2008, 02:15 PM
  #2  
Junior Member
 
Join Date: Mar 2008
Location: Haverstraw Marina, NY
Posts: 25
Default Re: Trailering MPG??

i have a 2008 dodge ram 1500 quad cab standard bed and get around 15mpg with daily use mainly city. I tow a 21ft center console and i noticed trailering it from cape cod in mass to the hudson river in ny that my feul economy was drastically reduced to about half of what it normally is. I noticed that under normal use i usually stay between 1500 n 2000rpms and when towing im usually around or above 2000rpms
screamskiier is offline  
Old 05-11-2008, 02:20 PM
  #3  
Senior MemberCaptains Club Member
 
Join Date: Feb 2006
Location: North NJ & Barnegat Bay
Posts: 6,316
Default Re: Trailering MPG??

Dodge ram with hemi and the boat in my Signature. NJ to Va and back to NJ 11.8 mpg. Not to shabby compared to my expedition at around 9 mpg.
pastaman1234 is offline  
Old 05-11-2008, 02:26 PM
  #4  
Senior MemberCaptains Club Member
 
Join Date: Dec 2005
Location: Tampa Bay Area
Posts: 1,973
Default RE: Trailering MPG??

bradv - 5/11/2008 3:52 PM

I have a 2008 F 350 Diesel Long Bed Crew cab.
Is that a 2wd or 4wd?
BiloxiGuy is offline  
Old 05-11-2008, 02:37 PM
  #5  
Senior Member
 
Join Date: May 2007
Location: Miami, FloriDUH
Posts: 2,024
Default Re: Trailering MPG??

I think drag has more to do with it. Unless there is a grade you are driving up.

Once at highway speed, it does not take a lot of energy to keep the trailer moving. Just enough to fight the rolling friction from the tires and bearings. The truck would not feel any more weight than the bearing and tire friction.

And then you add the wind. Resistance to winds at highway speed is a whole lot more than any rolling friction.

By the way in my truck - not hauling anything - I notice a big difference in 60 mph and 70 mph. I get a lot better MPG at 60 than 70. So I tend to drive at 60 now. What to pass me? Fine. Go ahead.

But to all those people who insist on sitting behind me flashing their high beams - realize I flip the rear view mirror up so I barely notice that. I am NOT speeding up just because you have to slow down. Deal with it
Lazy_Iguana is offline  
Old 05-11-2008, 02:41 PM
  #6  
Admirals ClubCaptains Club Member Admiral's Club Member
 
Join Date: Oct 2002
Location: anderson, sc
Posts: 18,565
Default RE: Trailering MPG??

I also tow with a 1500 Hemi and I will average around 10mpg on a local tow. I will sometimes reset the mpg gauge to check it.

I do tow my boat to Charleston SC several times a year and it is an "odd trip" from the upstate of SC to the lowcountry.
The first part of the trip is between home and Columbia SC and is all up and down hills and I will drop to around 8.5 mpg on that part of it but once I get below Columbia
the road flattens out and I can average a little better than 11 mpg if I take my time.

I use to tow with a 1500 Suburban and it would drop to around 7 mpg towing

Both tow vehicle are/were 4x4, I guess that does make a difference
tprice is offline  
Old 05-11-2008, 02:41 PM
  #7  
Senior MemberCaptains Club Member
 
Join Date: Aug 2002
Location: Onset, MA
Posts: 4,404
Default RE: Trailering MPG??

That's terrible . . . I get 18.5mpg towing a 20ft seacraft seafari (4000lbs rigged with gear + trailer) with a 1995 Buick Roadmaster Wagon.

Check out this project on ImpalaSS forum.

http://www.impalassforum.com/vBullet...d.php?t=139003

6.2L Diesel Swap into the Roadmaster.

50–55 MPH……….38MPG
65-70 MPH………..34MPG
65-70 MPH with 3,000 lb. trailer……..28MPG

Cadilliac Fleetwood had a rating of 7000lbs . . . only difference b/w the Buick Roadmaster and the caddy drivetrain was the 3.73 gears.

http://www.edmunds.com/cadillac/flee...merreview.html
BigShrimpin is offline  
Old 05-11-2008, 02:58 PM
  #8  
Senior Member
 
Join Date: Dec 2007
Location: Landlocked, Wi
Posts: 48,777
Default RE: Trailering MPG??

Grand Cherokee 4.7L. My old 19'boat weighed ~2,800# (single axle)andhad a windshield on top ofa highcabin. 55mph was about 14mpg, 65-70 I had to lock the overdrive and mileage went to ~11mpg. That rig was WINDAGE for sure.

Current21' boat is lower(less windage)but weighs 4,200#(tandem axle)and the mileage is about the same IF I can keep itin OD.

The other variable is tire pressure, keep'em up there.
GhostShip is offline  
Old 05-11-2008, 03:07 PM
  #9  
Senior MemberCaptains Club Member
 
Join Date: Dec 2004
Location:
Posts: 981
Default Re: Trailering MPG??

Bradv same truck same here( Except 2002) . I think the fuel computer has made the info more available and can be used to help us learn how to drive in order to get the best mileage possible. I have had friends (with no computer ) say they get about the same mileage at 75 as 55 or same towing not towing.... They just don't know!
mthomas is offline  
Old 05-11-2008, 03:10 PM
  #10  
Senior MemberCaptains Club Member
 
Join Date: Jan 2005
Location: canada
Posts: 689
Default Re: Trailering MPG??

Actually, I believe the Roadmaster story. In an old 83 6.2 diesel suburban I got 22 towing on the highway and 28 @ 65 mph steady unloaded. Aerodynamics of a brick. Limited power and smoky too. It ran 385,000 km before it rusted out with the motor still going strong. Based on that success I bought the successor 44,000 mile 99 GMC pickup 6.5 turbo with new injectors and although it has a little more power, I cannot get 22 unloaded.
Power sucks fuel is the lesson.
Torque and low diesel horse power will tow economically till you hit the mountains.


stapon251 is offline  
Old 05-11-2008, 03:16 PM
  #11  
Senior Member
 
Join Date: Nov 2004
Location: VA
Posts: 269
Default Re: Trailering MPG??

Wind drag for certain for my rig - 2003 Dodge 2500, 2x4, Cummins diesel, 6 spd manual, towing Albemarle 24 Express with (tall) hard top and curtains.
Flat ground, no tow, 60 mph = 23+ mpg
Flat with tow, at 60 = 12 mpg
Flat with tow, at 50 = 14 mpg
When once I drove it (empty ) to work on icey road (15 mph), got 30 mpg. Nice but not too practical.

Any comments on this???? ...Planing a 1600 mile round trip this summer and will be on the interstate doing about 55-60. Also planned to put a flashing yellow warning light on the stern. Just to check, I called the state police to ask about this... I was told (in a rather unfriendly manner) that since I was not a *commercial* towing vehicle it would be illegal for me to run a yellow flasher! Humm, since I am not making a profit, I should be less safe. Go figure. Think I am going to do it anyway, taking my chances to help prevent a rear end collision, especially at night.

Woody
capehaze is offline  
Old 05-11-2008, 03:29 PM
  #12  
Senior Member
 
Join Date: Dec 2007
Location: Landlocked, Wi
Posts: 48,777
Default Re: Trailering MPG??

Woody, I don't think there's anything they can do about a "slow moving vehicle" triangle. They come reflectorized(I think) and would light up when approached from behind. LEO's hate any flashing lights that aren't "normal".
GhostShip is offline  
Old 05-11-2008, 03:33 PM
  #13  
Senior MemberCaptains Club Member
 
Join Date: Nov 2004
Location: Galveston, Texas
Posts: 1,194
Default Re: Trailering MPG??

Towing a 27' Grady with a Ttop (about 9500 lbs) with an 06 Chevrolet Duramax HD2500 average about 9MPG @ 60 to 65 MPH
rotordriver is offline  
Old 05-11-2008, 05:05 PM
  #14  
Senior Member
 
Join Date: Jun 2004
Posts: 2,220
Default Re: Trailering MPG??

Capehaze.
What gear ratio have you got? Sounds like 4:10 I have a 2005 Dodge 2500 4X4, automatic, 3.73, and get 16 towing a 23' round trip from Charlotte to Holden Beach. Only changes, Super Chip programer to performance towing and a K&N air cleaner. I do use about 12 oz of Diesel Kleen every tank. While not towing, back roads, 25 mpg and Charlotte area, 22-23mpg. I use to have a Chevy, 350 4X4, 373 gear and the same round trip 6.6 mpg. Need to add, best fuel comsumption is less that 2100 rpm, keep it 60 or under.
saltfever is offline  
Old 05-11-2008, 05:11 PM
  #15  
Senior Member
 
Join Date: May 2007
Location:
Posts: 287
Default Re: Trailering MPG??

2003 Ford F-250 6.0L towing a 1993 Sea Ray Weekender about 9k loaded I get around 12 - 14 on highway as long as I am under 2k rpm's that is under 68mph. When going through the mountains from KY to Md or VA area I got 10 to 12 mpg.
dbric36 is offline  
Old 05-11-2008, 05:21 PM
  #16  
Senior MemberCaptains Club MemberPLEDGERPLEDGER
 
Join Date: Jan 2006
Location: Maui and SoCal
Posts: 7,103
Default Re: Trailering MPG??

I have more than "just a little" difficulty with the 38 mpg in the Roadmaster. They are more aerodynamic than a truck, but they are significantly heavier and less aerodynamic than a Passat, which will average 38.

I having been using an 6.0 F-250 to make a couple coast to coast trips. The difference between having the weight and drag of the boat back there is a real factor. I made one trip in a 4 x 4 and the next was in a 2 x 4 version of the same truck. The 2 x 4 was worth about 1.2 mpg better on the average than the 4 x 4. That has to do with drivetrain weight and loss. Even in 2 WD, there is frictional loss into the transfer case.

The mileage I got was directly related to my speed, which says the big factor is more a function of the aerodynamic drag than the total weight. Weight comes into it like crazy in starting and stopping.
kerno is offline  
Old 05-11-2008, 05:27 PM
  #17  
Senior Member
 
Join Date: Nov 2004
Location: VA
Posts: 269
Default Re: Trailering MPG??

saltfever
Well, to be honest, I have forgotten what my ratio is... First gear will redline (3K) about 15 mph. OTOH, sure is sweet coming up the ramp with 6000-7000#. Just have to ease out the clutch - and idle right up - no accelerator at all! I can get my mpg up to 15-16 (flat ground) if I stay below 45-50. The boat is about 5' above the top of the cab. Near 13 feet.

Woody
capehaze is offline  
Old 05-11-2008, 06:15 PM
  #18  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Dec 2007
Location: PBG, FL
Posts: 8,933
Default Re: Trailering MPG??

My 350 is a 4 x 4. cant imagine that truck without it. gets stuck looking at dirt weighing almost 8000lbs by itself. I have been playing around with towing and running empty trying to get the best mpg. turns out i end up saving about $25 per tank by slowing down just 5 mph to 65 when running on the highway only and doing regular around town driivng. It increases my average for the tank by about 3.5mpg which over a 39 gallon take is a big deal. I dont feel so bad now when i see my truck getting 12mpg now on the highway knowing that im not the only one. good stuff. anybody ever play with those wind deflectors that people running 5th wheels use or anything similar?
bradv is offline  
Old 05-11-2008, 06:15 PM
  #19  
Senior MemberCaptains Club Member
 
Join Date: Dec 2006
Location: kenly, n.c
Posts: 5,022
Default Re: Trailering MPG??

I average about 14-16 around 65mph not towing anything. Towing an old "91 stratos 2250 wa at 65 I averaged 11-12mpg. Towing the new boat in my sig pic, I only average around 8-9mpg. The truck is a silverado ss that comes with the 6.0 and 4:10 gears. This truck has never gotten good gas mileage which explains why it doesn't get driven all that much
vettnman is offline  
Old 05-11-2008, 06:19 PM
  #20  
Senior MemberCaptains Club Member
 
Join Date: Dec 2007
Location:
Posts: 11,181
Default RE: Trailering MPG??

bradv - 5/11/2008 3:52 PM

I have a 2008 F 350 Diesel Long Bed Crew cab. Running 65 mph on the highway with no load i can get 21 mpg. Running 65 mph with 2000lbs in the bed i can still get around 19 or 20 mpg. However dragging my 21ft boat i get around 12mpg. I know it has more drag and the whole package probably weighs in between 5 and 6k but what is anyone else seeing when trailering?? Does a heavier boat change the efficiency as much as the aerodynamics? Just curious.
2002, 2500HD Dmax, Crew, short box. I average right at 18 mpg in town unloaded and 20 mpg with cruise set at 78 mph. Never drive 65 for long enough (unloaded) to get a good mpg number, but i have seen 23 mpg when driving back roads and keeping it 55-70 mph.

I get 10 mpg when I tow my offshore boat (probably 9,000-10,000lbs) with cruise set at 70 mpg, I get 14 mpg with cruise set at 75 towing my marsh boat (approx. 3500 lbs). The marsh boat is on a tandem trailer and the offshore boat is on a trip axle trailer.

If you're getting that kind of mpg with an '08 F250, you should jump for joy. Everything I've read from other late model f250 diesel owners doesn't even come close to that!
Back-in-Black is offline  

Thread Tools
Search this Thread