MPG Reality Check

[ebirder2000@...]

Bob, I don't dispute your method or your finding at all. My only comment is, that mileage seems too low.I would expect thatyour mileage would be closer to 8mg. But,that's only based on other folks bragging including my own,that I have observed.

Steve (at Painted Rocks campground). Temp 80 degrees with absolute clear blue skies.

In a message dated 2/12/2010 12:22:01 P.M. Pacific Standard Time, sundance101@... writes:

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