You may have just met a hypermiler.
Hypermiling is the practice of using modified driving techniques to get the maximum mileage possible. The practice is increasing as gas prices soar.
The worrisome part of this story is that an increasingly large group of hardcore fanatics have taken up hypermiling using potentially dangerous methods including shutting the engine off going downhill (making power brakes and power steering nearly useless), drafting behind trucks and coasting through red lights.
Promoted on a growing number of Web sites, hypermiling includes pumping up tires to the maximum rating on their sidewalls, which may be higher than levels recommended in car manuals; using engine oil of a low viscosity, and the controversial practice of drafting behind other vehicles on the highway to reduce aerodynamic drag -- a practice begun a few years ago by truck drivers.
The "advanced" techniques of hypermiling are in addition to well-known approaches including keeping speed down, accelerating gently, avoiding excessive idling and removing cargo racks to also cut down on aerodynamic drag.
During the later years of the old Mobil Economy Run, some drivers even went so far as to sandpaper the bottoms of their feet to increase sensitivity helping them accelerate more slowly and brake more gently. Will hypermiling come to this?
The Mobil Economy Run was an automobile fuel economy test that began in 1936 and continued until 1968. 
The photo above shows a Plymouth Valiant competing in the 1964 Mobil Economy Run.
Cars made in the United States competed in several price and size classes in a test of fuel economy. The cars were driven on cross-country runs through normal traffic.
More on hypermiling here.
A picture of my cave
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