Thread: Fuel MPG

  1. #1
    Join Date
    Dec 2009
    Location
    SE Alaska
    Posts
    185

    Default Fuel MPG

    We've been having a discussion on the hardside section about mpg etc. I know many of the hardsides are HEAVY and milage is cut by weight, but I'd like to hear about air resistance of a hardside vs pop-up and mpg. There are a pile of other variables to consider also on milage probably driver being the most important.
    My camper is a real light weight 1994 9.6 Northern light that sits in a 2006 Dodge Cummins Quad cab, auto trany. Without camper mpg runs 17-20 depending on terrain with camper we get 12-14 again terrain makes a difference. I always drive by RPM and that goes 1700-1800, which means I drive like grandma to some folks out there. The weight of the camper is really nothing for our engine, but I do believe the air resistance IS a major factor of mpg.

  2. #2
    Join Date
    Nov 2008
    Location
    Hillsboro Oregon
    Posts
    692
    Obviously to really get an accurate comparison, you'll need to find someone who has hauled a hard side and pop-up on the same truck, same driving style, etc.
    I do believe that the wind resistance plays a much larger part than weight as well. If both a hard side and pop-up camper are equal width, you're still interrupting the airflow over (and around) the cab in the same manner, and still left with a flat surface on the back side which causes a lot of drag. It's hard to believe that an extra 1-2' of height (all else being equal) is really going to equate to much difference in mileage. Hauling the hard side camper on my F150 only netted a 3mpg loss, even at 70-75mph, and I doubt a pop-up would be much different...?
    SOLD 2012 Jeep Wrangler Rubicon Unlimited - Ursa Minor J30 camper, 3.5" AEV/Synergy/Metalcloak lift, 35s, 4.88s, Tera44 front axle w/ARB RCVs and Reid knuckles, Fox ATS, Warn Zeon 10s on Expedition One full width bumper, Truck Lite and JW Speaker LEDs, sPod.

  3. #3
    Join Date
    Apr 2011
    Location
    DFW, TX
    Posts
    4
    I don't see any difference with my pop up in, but nearly every tank with it has also had my car hauler behind it.

    I'm sure wind makes a difference, between a pop up and hard side, plus the 1k differnce in wieght.

  4. #4
    Join Date
    Jun 2005
    Location
    Tucson, more or less.
    Posts
    2,363
    It's difficult to get honest mpg numbers out of people, but I included some carefully documented figures from a Cummins-powered Dodge equipped with a Four Wheel Camper here:


    Speed versus economy


    Brian DeArmon just got back from installing trail cameras in the Sierra Madre with his Dodge and FWC; he reported 17.7 on the road and 11 on the four-wheel-drive climb to the property we're surveying. Not bad road economy with an automatic.
    1973 FJ40, 1974 Series III 88, 1982 911SC, 1970 Triumph Trophy, 1985 300D, JATAC, Thorn Nomad.

    Overland Expo


    ConserVentures

  5. #5
    Join Date
    Jun 2007
    Location
    Reno, NV
    Posts
    104
    I posted this in that other thread:

    2000 GMC Sierra 2500 (3/4 ton), 6.0L gas V8, 4L80E (4-spd) automatic transmission, 4WD, extended cab, longbed, stock suspension, 245/75/16 wheels/tires (stock size), no heavy add-ons (i.e. stock bumpers, no winch), with Northstar TC800 pop-up camper (8-foot length, fits entirely within bed, but tailgate must come off). Most of the time when traveling, there is a large 4-bike rack on the rear hitch, with 2 to 4 bikes on it -- not sure how much this matters in terms of MPG on this truck though.

    Real world MPG at 65mph max: 12 hwy, hand-calculated. I've seen 12.5 (slower highways, 55mph), and occasionally 11.5 (higher speeds, say 70-75), but almost all of the time it's right around 12 mpg. Truck has plenty of power, but I try to go easy on the accelerator to keep the MPG as good as possible.

  6. #6
    Join Date
    Feb 2008
    Location
    Woodland, CA
    Posts
    403
    With my last truck, this is what I was getting for average gas mileage . . .

    2000 Ford F-150, Extended Cab, Long Bed, 5.4L V-8 Gas

    14 - 15 mpg just running around empty

    12 mpg with the Grandby Pop-up Camper (approx. 1000 lbs)

    10 mpg with the Six-Pac Hard Sided Cabover Camper I used to have (approx. 1600 lbs.)




    .
    Stan Kennedy

    stan@fourwh.com

    Four Wheel Pop-up Campers / Six-Pac Campers
    www.FourWheelCampers.com
    www.Six-Pac.com
    109 Pioneer Avenue
    Woodland, CA 95776
    1-530-666-1442 - phone
    1-800-242-1442 - toll free
    1-530-666-1486 - fax

  7. #7
    Join Date
    Jan 2010
    Location
    San Diego
    Posts
    1,000
    My '07 Dodge CTD w/TC 800 Northstar and 285-75-17 Toyo MT's averages 13-14 mpg in town. Slight increase in all highway travel. Chuck the camper and I pick up 3-4 mpg.

    My buddy's '05 Dodge CTD w/SixPac 9.5' hardside and 35-12.50-18 Toyo MT's averages 10 mpg in town and maybe 11-12 mpg on the highway.

    Camper configuration makes a huge difference and the added drag of the MT's don't help either.

    My 1999 CTD w/DTT auto,Edge EZ and Mach 1.6's got identical mileage to my '07.

    I'm still hoping a 265/275-80- 17 comes out. It would be similiar in size to a 265-70-19.5 but without the cost,weight and G-rating.
    Last edited by Regcabguy; 04-08-2012 at 10:10 PM.
    2007 Dodge 2500 Regcab 4wd 5.9 CTD. G-56 , TC800 Northstar popup 24/7.

  8. #8
    Join Date
    Sep 2011
    Location
    Florida
    Posts
    5
    Iv'e hauled both hard and soft side my truck is a 2000 Dodge ram 3/4 ton full size ext. cab with a cummins diesel six speed manual tranny, with out a camper on my truck I get 21 MPG at 73-74 MPH with either of these campers my mileage dropped to 15.5 at 73-74 MPH, the hard sided camper weighed 2300 lbs. the soft sided camper weighed 1800 lbs. both of these were dry weights.

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