How many gallons in a 1/4 tank of gas?

[themechanic]

If the fuel gauge was linear it is easy to calculate but it's not.

 

[RemCharger]

Look up the capacity spec of whatever type of vehicle you have in mind and divide by 4.

 

[themechanic]

Look up the capacity spec of whatever type of vehicle you have in mind and divide by 4.

That's what I said is correctly calculated assuming the gauge is linear. Correct me if I'm wrong but isn't the gauge non-linear?

My tank is 19 gallons and is wedge shaped.

69 Coronet

 

[DeltaV]

My 1970's Mopars seemed to be fairly linear.

GM's of the same era and into the 1980's were definitely not linear.

***
I have seen conflicting capacities for my '79 300, but I once fueled it with 22 gallons.

 

[RemCharger]

That's what I said is correct assuming the gauge is linear. Correct me if I'm wrong but isn't the gauge non-linear. ?

I do not believe the sending unit rheostat is wired to accurately reflect the shape and volume of the tank at all levels. If it's a 16 gal tank, the last 5 gals might show as a quarter.
Or something else.

 

[DeltaV]

From FABO guys:

Fuel Gauge Sending Units compared

 

[RemCharger]

From FABO guys:

View attachment 1910602

Fuel Gauge Sending Units compared

Thanks for that, post #3 and 16 are the good take aways. Looks like they did try tailoring the winds to the changes in in volume/ height.

 

[autoxcuda]

When tanks gets to 1/4 full, then fill it up.

Take that amount you filled it up and subtract from the 19 gallon tank.

If you want to know 1/2 full, same thing...

 

[kiwigtx]

Bear in mind also that the float is in the deepest part of that shape of a tank. So 1/4 (which = approx 4.5 gallons) might show as a lot less than a quarter of a tank.

It also depends upon the stance of the car and whether or not the driver is in his/her/they/them seat.

 

[Kern Dog]

Bear in mind also that the float is in the deepest part of that shape of a tank. So 1/4 (which = approx 4.5 gallons) might show as a lot less than a quarter of a tank.

It also depends upon the stance of the car and whether or not the driver is in his/her/they/them seat.

Sending units can also be shaped wrong. This A body sender and tank.....

The float was at least 1 1/2" off the floor, the sock and pickup was about 1 1/4". This meant I could have 2 or more gallons before the gas even touches the float.
I reshaped it....

There wasn't much I could do to the float unless I lengthened the arm. I did bend the pickup though.

 

[themechanic]

I'll probably just empty the tank and add a gallon at a time and use the MeterMatch box to calibrate the fuel gauge noting how much gas us in the tank at each increment on the gauge. Like the guy on FABO did as seen in this photo from there.