Featured MPG Testing is a bit of a Mystery

Correct!

The 2 gallon, 70 mile gas range means about 1 hr 15 minutes between refueling. But it turns out Briggs and Stratton makes a 2 gallon, spare gas tank that fits in the frunk and still leaves room for the tire patch kit.

It has a filler cap with about a 1.5" hole that normally has a plastic cover to prevent gas spillage.

I'll fabricate a disk with gasoline resistant gaskets and 3/8" NPT fitting. Then a 3/8", braided gas line terminates in a male "flat face coupling". Then a similar configuration will be installed on my spare, gas filler pipe just before it goes into the existing gas tank. It will have a similar NPT fitting into the female "flat face coupling." It is critical that there be a positive slope from the lowest filler pipe nipple through to the bottom of the 2 gallon, Briggs and Stratton, auxiliary tank.

Around town, the auxiliary tank will be stored in the car port. But when we go on a trip, it and a padded cradle will go in the frunk. I'll fill both tanks; couple them together, and; lay the Briggs and Stratton tank so the filler cap is the low part.

Gravity will transfer the gas using the 'hampster water bottle' principle. When the level of gas in the filler pipe nipple is low enough, a bubble of air/gas fumes will flow up the hose releasing an equal volume of gasoline into the main tank.

My thinking is going from 2 gallons to 4 gallons will extend the gas range to ~140 miles, about 2-2.5 hours depending upon cruising speed and cut out half of the fuel stops. This will significantly improve block-to-block speed which now suffers because of the 1-2 mile, detours to gas stations off the Interstate.

Bob Wilson