Does a diesel pusher get 11 mpg?

[Bob86ZZ4]

My neighbor has a Phaeton 40' d/p built on a Freightliner chassis. It's got 4 slides. I don't know what motor (I think I asked him and he thought it was a Cummins?) Allison auto trans. He said he cruises at 65 mph usually. he claims he gets 8-11 mpg. Is that possible? Seems kind of high to me. I'm very meticulous about checking my mileage all the time. I always write down everything, fill the tanks every time I fuel up, and do the math. I cruise at 66-68. About half the time I'm pulling an enclosed car hauler, total weight of that is approx. 7k lbs. I know my rig is 26k lbs. The worst mileage I've ever gotten is 8.1 mpg. The best I've gotten is 9.7. I don't think he should be getting better mileage than I get, should he? Not that I care much about my mileage because I'm perfectly happy with what I get and I've got tons more reserve power than he's got. Just thinking his computer might be lying to him. He doesn't check mileage properly, he just goes by the dash computer I guess. His rig should be heavier than mine, he's got a torque converter, and a much less powerful motor. Any thoughts from you guys on it?

 

[geofkaye]

...tis' possible BUT likely ???? unless he is doing 35-40 when he reads the dash computer.....my truck fluctuates all the time from 4 something to 90 something all in the same mile depending on traffic and my lead foot/leg.....you can't tell without going and getting a direct measurement and that is time consuming-and for what? bragging rights?.....I average in the nines most of the time and might get a 11 from time to time....but I really don't care that much what mileage I get anymore....geofkaye

 

[Doc Weaver]

Well...............in the 80's I had an Eagle that got 12mpg and my Freightliner gets as much as 11.9mpg. Even though that is a true statement, an explanation would be proper. The Silver Eagle was a fluke. I had a buddy that had a brand new Eagle with a V892, and a 4 cylinder diesel generator. It got 1 to 4 mpg.

The first trip in the Freightliner I drove 70 mph and got 8.6 mpg. The next trip: the road was level, I went 65 mph, did a bit of drafting, and got 11.9. High numbers are possible if you work at it real hard.

On the last trip I was in a hurry and gave it the GK hammer......I purposefully didn't check the MPG.

Doc Weaver