Fuel mileage estimate for Ocelot

[Henry]

Can you please give me an estimate on fuel mileage on a F150 for a Ocelot or Panther ATC, (or similar size truck, GMC 1500 or Ram 1500).
I realize there are a lot of variables camper weight, terrain, driving styles, engine types, so I'm more interested in percentage decrease of fuel mileage from "daily commute" with no camper to fully loaded camper on a trip.
Say something like 60 mph, rolling terrain, interstate.
I just trying to get a feeling of what to expect; 25% less mpg, 40% less? I know when I haul a 2500 lb trailer my fuel mileage is down about 40%.

Thank you for your help.

 

[ski3pin]

A little different truck and camper but may help with a ballpark start. Our mileage drops 10% with the camper on.

 

[iowahiker]

We are not an exact match to your question but applicable. Our regular cab half ton 5.0 V-8 4x4 HD weighs 5500 pounds which is similar to extended cabs. Our lightly optioned Granby weighs 1100 pounds without the jacks empty and our total loaded and wet weight is 7500 pounds including two people. We get 19-20 mpg highway unloaded at 60-69 mph. We get 15-16 mpg highway loaded (total weight 7500 pounds) at 60-69 mph. The 15-16 loaded mpg can be subdivided to 15-15.5 mpg east of the Mississippi at lower altitudes and higher humidity while we get 15.5-16.0 mpg west of the Mississippi with lower humidity and higher altitudes (that must be where that saying "go west..." comes from). All mpg's are based on tank fills and odometer readings and not the engine computer which reads 1 mpg higher on average.

 

[simimike]

Figure on a 4 to 5 MPG drop with the camper. Any aerodynamics that the truck has pretty much go out the window. My new Chevy with a 5.3L V8 is window sticker at 22 HWY 15 City, ha, good luck getting that with a camper. Once the camper is installed I'm thinking maybe 15 or 16 MPG HWY. Anything more would be gravy. Hope this helps.

Mike

 

[Henry]

Thanks for the replies. Iowahiker, your numbers are quite applicable to my weight estimates, so that really helps.

I'm going with 25% reduction in fuel mileage fully loaded vs unloaded.

 

[MarkBC]

My rig is rather distant from your situation -- Ford F250, 6.8-L V10 gas with a FWC Hawk...but FWIW here's another data point:
I got 14 mpg without the camper and I get 12 mpg with the camper. That's highway driving (over gentle terrain) at no more than 65 mph in 2wd.

As has been said, the camper makes the rig UN-aerodynamic. So, driving fast is going to reduce your fuel mileage more than it would without the camper -- because of the increased air-drag (which increases at faster-than-linear with speed). So even on Interstate freeways with 75 - 80 mph speed limits, I keep it under 70 -- usually not more than 65 mph.