MPG Reality Check

[Chuck Wheeler]

Bob,

Our 82 has averaged 9.2 on a little over
27,000 miles we have run without the diesel generator. It is non-turbo
210hp. We never tow and I usually have the cruse set on 60. Here in
the middle of the country it is a lot flatter than where you are. I use
the GPS and speedometer for mileage and they are usually within a couple of
tenths. Individual fill ups have been between about 7 and 11 mpg so I don’t
pay much attention to one tank. Most of this time it had Dunlop tires on
it at 115 on the front and 100 on the duals. (I raised the pressure after
weighing)

Two years ago I drove a 77 Eagle
entertainers coach from Bremerton WA to Denton
TX for a friend and used 202
gallons to cover 2211 miles at what ever the prevailing speed limit was.
It was a 6V71 with manual 4speed and a splitter. Been jealous of him ever
since.

- Chuck
Wheeler-

1982 FC 31SB Fort Worth TX

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From:
WanderlodgeForum@yahoogroups.com [mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of freewill2008

Sent: Friday, February 12, 2010
2:17 PM

To:
WanderlodgeForum@yahoogroups.com

Subject: [WanderlodgeForum] MPG
Reality Check

Finally, after 7 years, I filled the fuel tank to the
top, drove 1015 miles, and filled it again. The 167 gallons calculates to about
6 MPG.



The method has plenty of potential for error. The odometer reads low and I
don't have a GPS. I used the Google mileage plus 5% to account for wrong turns,
finding RV sites, etc. The route was Brookings, OR to Q by way of Hwy 101 and Malibu, CA.



The tank is so big that I figure the fill could be off by as much as 10%. If
the fill-up were 10% low, the MPG would have been 6.7. If the fill-up were 10%
high, the MPG would have been about 5.5.



Other details: 1984 FC31 with California
210HP turbo 3208. Road speed about 58 MPH. 4.89 gears. 11R22.5 Michelins at 105
and 95 PSI. Towing a Honda CRV. Air filter has about 5000 miles. The air intake
is the enlarged version designed for the 250HP turbo engine. Never blows any
black unless I make an operator error.



To achieve the 10 MPG sometimes suggested for the FC, my mileage estimate would
need to be off by almost 700 miles, or the fill-up would need to be off by
almost 70 gallons.



I'd be interested any anyone else's MPG observations and the method used.



Bob Griesel '84 FC31 WLII WA