When the tank is half full, even the baffles cannot stop the sloshing, which keeps the float higher on average. Since the float does not react instantaneously, it continuously reads high. The lower the tank gets, the lower the momentum of the sloshing fuel, so the float does not get pushed higher as before, and it appears the tank is draining faster.

After I make a right turn, my fuel level will read high for 30 seconds or so, a left turn and it will read low. Different levels of crown in the road also effects readings. I always appear to have more fuel if I'm in the left lane of a highway that is peaked in the center lanes.

My tank takes a long time to go from the 5/8 mark to the 1/2 mark. The 1/2 mark is in reality more like the 1/3 full position.

Watching the fuel level can drive you insane, you are better off installing a mechanical oil psi gauge and studying that and seeing if you can guess your speed and outside temp from the reading.

 

When the tank is half full, even the baffles cannot stop the sloshing, which keeps the float higher on average. Since the float does not react instantaneously, it continuously reads high. The lower the tank gets, the lower the momentum of the sloshing fuel, so the float does not get pushed higher as before, and it appears the tank is draining faster.

:huh: Did you make this up all by yourself? :wedgie:

 

Thanks Landyacht

I now have an answer,Thanks !It has bugged me for every vehicle I have ever owned!Its a stupid question I never addressed and has driven me crazy for years wondering why!
Thanks again!
Myles

 

The gauge float operates a variable resistor in an arc and the readings are non-linear, so the change in the gauge reading will be non-linear also.. (the rate of change is not constant).

 

The gauge float operates a variable resistor in an arc

Correctamundo, you're on the right track.

 

Hi Alloro

I was just bored and wondered why tanks in every vehicle I have owned have read faster and slower in consumption since I was 16 1/2yrs old.It annoyed me and wondered wiser minds might have the real answer!I could only guess!And so they have!
Thanks,Nice to talk with the gang Again!
Myles

 

It just makes you understand that as the tank gets closer to E, keep looking for a fueling station fast, don't put it off.

 

Sloppy tolerances of mass production.
:gr_patrio

 

Hi

You Know it!!!!!!!!!!!!!!!!!!!!!
Wish it was older!
Myles

 

Maybe a visual will help. In this drawing note the two horizontal lines in both the top and bottom halves of the drawing. These represent before and after fuel level marks. The circle is the arc that the float moves in, and the red line is the float arm. In the top half, the float arm moved down with the fuel level. In the bottom half, the float arm also moved down with the fuel level, but it also moved to the right. In the bottom half the float arm actually traveled further for the same drop in fuel level. This is why the fuel gauge moves faster as the tank gets closer to empty.

 

hi

That does make sense!
Thanks buddy!
myles