376 Miles per Gallon--in 1973

Those old enough to remember the original Shell Answer Man might also remember Shell's record-breaking test car that achieved an astounding 376 miles per gallon, back in 1973.  I myself vaguely remember reading something about this as a child, back when Shell used to print those little yellow booklets as a tear-out feature inside popular news magazines.  I came across the Shell record once again in college, while studying fuel efficiency as part of an engineering course.

As it turns out, the original car apparently still exists, and can be seen in numerous photos at this website, 376milespergallon.com.  Although I think the mileage record has long since been broken, it’s interesting to wonder how Shell achieved 376 mpg, and did so over 35 years ago with a car based on a 1959 Opel chassis.  The question naturally arises, why can’t such mileage performance be made commonplace in today’s cars? 

The trick, of course, is to remember that the Shell car was just that, a trick, meant simply to demonstrate what could be done with a car built solely  for the purpose of maximizing mileage.  The Shell engineers did, in fact, achieve the mileage record, but did so in ways that few drivers now would want or accept in their own automobiles, as comfort, safety, performance and aesthetics were completely ignored:

• to save weight, the complete interior of the car was stripped, leaving only a hard plastic chair for the driver;
  
  
• the normal transmission and drive train were replaced by a simple, two-speed gearing system using a chain drive, like a bicycle;
  
  
• suspension elements, like springs and shocks, were also removed to save weight;
  the rear wheels were replaced with a pair of wheels at the centerline of the  vehicle, giving the car an odd, backwards-tricycle-like stance;
  
  
• the engine was wrapped in asbestos blankets to improve the thermal efficiency of the engine (which likely would destroy the engine over time, due to the thermal stress and overheating);
  
  
• aerodynamics were not given any thought, as the car was not meant to go much faster than 35 mph; and
  
  
• the driving technique employed during the record-setting run was an extreme form of pulse-and-glide:  the car was run up to about 35 mph, and the engine was then shut off, until the car had nearly coasted to a stop (the driving technique also helped prevent engine overheating, since the engine only ran for relatively short periods).

Needless to say, few drivers today would accept such conditions or performance in their family car.