Originally Posted by JosephineJ79
Here are good reasons for shutting off the electric fuel pump.
1. When the mechanical pump fails, you will find out immediately that it is not working. Why have to wait until the next pre-flight run up?
2. Shutting off the electric pump is a good way to test the vapor pressure of non-leaded gasoline. Fill the tank with your favorite brand of automotive fuel. Shut off the electric pump soon after takeoff and climb until the engine sputters. Note the altitude. Land, then repeat the test with other brands of fuel.
3. Save electricity.
And counterpoints for NOT having it switched:
1.) One more switch simply means one more switch to forget or fail.
2.) The system was designed to run with the electric pump on all the time.
3.) You'll have less chance of the engine sputtering at altitude to begin with.
4.) The amount of electricity used by your fuel pump will not make a measurable difference in your speed, fuel consumption or anything else.
I very much prefer to do my testing on the ground rather than in flight, thank you.
Just my $.02 worth, keep the change.