Tilted Gasoline Filling Stations

The one useful thing that I learned from my crazy uncle was how to pump another gallon or two of gasoline by shaking the whole car to let the air out of the top of the tank. I later learned to not do that with passengers in the car--he somehow always got away with it.

Some gas station operators have noticed me *ding*-ing the "pump-finished" signal a few extra times, but seemed glad enough to sell me a few more dollar's worth of gasoline. I started to design a car-shaker for them to increase their sales, but decided that there is a far simpler method to get the bubbles out of a gas tank.

Quite simply, build the parking area around a gasoline pump to slope downhill away from the pump by a few degrees. This would allow the air that accumulates at the flat top of almost all gasoline tanks to bubble out. (Almost all drivers park with the filling port toward the pump, except me when I drive my mom's car.) The exit of the air would allow another gallon or so of gas in the tank for anyone who is filling it all the way up. Which would mean a few more dollars for the gas station owner.

There may be some good safety reasons for not filling a gas tank all the way up, but I am assuming that gas station owners will prefer to sell more gas than to worry about customer safety down the road.

The cost of building a station with a slight slope is probably no higher than the cost of a level station. The cost of retro-fitting a slope to an existing station will vary.

The ideal slope will be only a few degrees. The slope should not be enough that customers have difficulty getting car doors open or climbing out.

(My apologies to British readers for using American terms. Please substitute, where appropriate, the words "petrol", "pound", "horseless carriage" and "firkin". :)