Mobil Economy Run was an event that took place every year from 1936 (except during World War II) to 1968. It was designed to provide real fuel efficiency numbers during a coast to coast test on real roads and with regular traffic and weather conditions. The Mobil Oil Corporation sponsored it and the United States Auto Club (USAC) sanctioned and operated the run.
The Mobil Economy Run determined the fuel economy or gas mileage potentials of passenger cars under typical driving conditions encountered by average motorists. This is in contrast to the current method of computing fuel consumption by the United States Environmental Protection Agency (EPA) by running cars on chassis dynamometer in a climate-controlled environment. To prevent special preparation or modifications to the participating automobiles for the run, the United States Auto Club purchased the cars at dealerships, checked them and if certified as "stock", their hoods and chassis were sealed. The factory gas tank was disconnected so fuel use could be accurately measured by using a special tank mounted in the trunk. Because of the many types of automobiles, the Mobil Economy Run had eight classes based on wheelbase, engine and body size, as well as price. The leading automakers provided drivers and in each car was a USAC observer to prevent any deviations and penalize for traffic or speed limit violations. Women were permitted to participate in the Mobil-gas contest only since 1957.
The event was a marketing contest between the automakers. The objective was the coveted title as the Mobilgas Economy Run winner in each class. However, starting in 1959, entries were judged this year on an actual miles-per-gallon basis instead of the ton-mileage formula used previously, which favored bigger, heavier cars. As a result, compact cars became the top mileage champs. In the 47-car field for 1959, a Rambler American was first - averaging - while a Rambler Six was second - with an average of - for the five-day, trip from Los Angeles, California to Kansas City, Missouri.
The efficiency of models as AMC's more compact Ramblers caused them to be all but banned from the race. As a result, Ramblers and Studebakers were put in a separate class. This was because the 'Big Three' auto makers (General Motors, Ford, and Chrysler) did not have competitive cars at the time and were trounced in the fuel efficiency rankings.
Automakers tried to "prepare" their cars to achieve better results. Moreover, the factory supplied drivers were highly trained and experienced to drive in a manner that conserved fuel. An average driver in the same car and over the same course would be lucky to achieve the Run's results.
The event had other problems, including a fictional character who was hit by an automobile. "It was terrible," she says. "The driver couldn't stop because he was competing in a Mobilgas Economy Run." in the 1966 novel entitled "Balloons are Available" by Jordan Crittenden.
Mobil entered the United Kingdom service station market in 1952, as Mobilgas. It copied the annual Economy Run from the US. However, in the 1970s it was taken over in the UK by Total S.A., however the event was also discontinued in the UK after just a few years.
The Mobil Economy Run is used to explain the claims made for United States Patent # 3937202 - an "Economy driving aid: