Fuel MPG

[sisu]

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.

[brianjwilson]

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...?

[BAR0N]

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.

[Jonathan Hanson]

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.

[olsen_karl]

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.

[Stan@FourWheel]

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.)




.

[Regcabguy]

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.

[barndog]

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.