I don’t need to tell the two of you, but for the benefit of the others here... we have had a Piper Cherokee 140 for the last 20 years which is one of the very easiest planes to fly. Fuel exhaustion is the leading cause of “engine failure” in Cherokees as well as pretty much every other General Aviation aircraft.
Our gauges have never let us down, but we still don’t trust them... we always do a visual check of the fuel in the tanks before taking off as part of the preflight. We also use a rigid plastic tube that is precisely calibrated to measure the amount of fuel in each tank. It is used by dipping it to the bottom of each tank and then holding your thumb over the upper end as you pull it up and read the level.
We don’t always keep the tanks full. Our tanks have a tab you can see when you look into them that indicates when each tank has 18 gallons. Because the Cherokee 140 has only a 150HP Lycoming O-320 the amount of weight that you can get into the air with you is limited. The standard amount of fuel is considered 36 gallons which weighs 216 pounds, with full tanks one is carrying 50 gallons which weighs 300 pounds.
With the Cherokee one uses first one tank and then the other. We know what the normal fuel burn is for a given power setting and we keep a log with the time spent using each tank. As fuel is used out of each tank that wing becomes lighter and it is necessary to use more and more rudder trim to keep plane flying straight hands off. This makes it easy to remember which tank is getting lower on fuel.
Unlike RV-6s Cherokee 140s do not ever leap into the air. Depending on the temperature and altitude the plane may perform “well” with full tanks. If it is hot and the plane it as at a high altitude it may not perform very well even with very little fuel in the tanks.
On cool mornings I can get to 800feet by the end of my 4000 foot runway.
In the middle of July maybe 500feet.
36 gallons and cruze at about 145 with 3/4 throttle.
I’m sipping maybe 4.5 gallons and hour and can not go long enough to run out without stopping for a rest room break.
Always leave at least 1/3 and fill up for safety sake.
I usually fly one hour on one tank then switch over to keep the plane balanced.
I live and fly out of FL37.
Coolest thing I ever did as a pilot was to fly up to 10,000 feet about ten miles north of Sebastian with my son and we watched and filmed a shuttle launch.
Way kool.