"High Tech Misfit" <me@privacy.net> wrote in message
news:eoqasmcovw1b$.dlg@hightech.misfit...
> mpwilliams wrote:
>
>> EPA mileage estimates are determined through dynamometer testing in a
>> laboratory, and among the factors reducing actual gas mileage that are
>> not
>> considered in these tests are rolling resistance of unpowered
>> wheels/tires,
>> aerodynamic drag, non-productive operation (engine running with no
>> forward
>> progress, as occurs at traffic controls or in stop-and-go traffic),
>> ambient
>> temperature (affecting intake air density), and altitude (also affecting
>> intake air density). City and Highway mileage ratings determined in the
>> laboratory are adjusted downward by 10 and 22 percent, respectively, in
>> an
>> attempt to compensate for these and other factors, but Consumer Reports
>> have
>> consistently determined, using their own mileage testing protocol, that
>> the
>> EPA mileage estimates posted by automakers for new vehicles are
>> optimistic,
>> sometimes by as much as 30-40 percent.
>
> And yet, my '93 Accord consistently got 10-20% above EPA estimates on the
> highway. Go figure.

This may seem like an asinine question, but what is your process for
calculating actual fuel mileage? Also, what is the elevation and range of
mean daytime temperatures where you live? I ask the latter because lower
elevations and lower mean ambient temperatures, in comparison to the
location of the automaker's test facility, will result in comparative
mileage improvements, ceteris paribus, due to more dense fuel/air mixtures
prior to combustion.