[A/S] MPH MPG Experiment

["Dick Martin" <suburbandvr@xxxxxxxxxxxxx>]

I just completed a cross country trip from Southwestern Oregon to Ohio to
visit the Air Force Museum and the Airstream factory.  After hearing how
wind resistance has a major effect on fuel efficiency I decided to do my own
experiment.  Prior towing of the 10,000 pound Airstream has primarily been
between 62 and 70 mph with a GMC Duramax/Allison 2500HD pickup.  Fuel
consumption has usually been between 10.0 and 11.0 mpg depending on terrain.
The desire was to see what would happen driving at 55 mph.  The hardest part
was on the Interstate in Colorado and Kansas when the speed limit was 75
mph.  Here are the results.
 
First leg - Oregon to Reno - 10.50 mpg - 4000' mountain passes, speed
average 62-65 mph
Second leg - Reno to Utah - 12.28 mpg - rolling hills some low passes, speed
55 mph
Third leg - Utah to Denver - 13.21 mpg - high passes, speed 55 mph
Fourth leg - Denver to Missouri - 15.52 mpg, flat lands & no head winds,
speed 55 mph
Last leg - Missouri - 13.61 mpg, rolling hills, speed 55 mph
 
Overall average at 55 mph was: 2341.5 miles/171.385 gallons = 13.66 mpg.  At
10.5 mpg it would have taken 223 gallons or 51.615 more gallons of fuel at
about $2.16 a gallon, an extra $110.  Instead of $483, fuel cost was $372;
that is a reduction of about 23%.  It was a real surprise to realize that
big of a fuel consumption reduction.
 
Putting it another way it reduced the effective cost of diesel from $2.16 to
$1.66.  Being retired and taking my house with me the extra travel hours are
not a big thing to me so I will be the slow 34' Airstream in the right-hand
lane from now on.  It won't be easy!!!!!
 
Dick Martin
  http://home.earthlink.net/~DriveAbout