There are a few other variables in calculating fuel economy (I assume that you are measuring miles on your odo vs. gallons it takes to fill a tank.

-Wear on the nozzle - they are not computer-controlled closed-loop systems that automatically adjust for fuel liquid temperature, flow, tank pressure etc... nor do they recieve "gentle so it lasts forever" handling imho.

-position of the nozzle in your car - the nozzle is shut off by a vacuum sensing port on the nozzle - this might trip differently if the nozzle is slightly pushed in or out a bit differently, or if the fuel foams up more (as affected by...

-Temperature outside - colder operation affects power (and fuel volume...), which affects how much farther you push the pedal down....I don't know about you but the thermometer has been impersonating a basketball here in Cincinnati.

I think that you are doing all you can. I figure that an average of 3 mpg calculations is a MINIMUM for measuring fuel economy. You have done well to minimize variables, but I think that there are still too many.

Your readings sound about right for a lightly driven NA 300D. I got the same in my 240D and the turbo guys rarely make it up to 28.

-John

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2009 Honda Odyssey EX-L
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