Why does the first half tank of gas seem to last longer?

[deevergote]

I've noticed this with every car I've ever driven. The first half tank goes forever. The second it hits the halfway point, it seems to head to E very quickly!

I just filled up my 10.6 gallon Fit tank. The needle was barely past 3/4, but I filled it with 4.2gal!

Is there any reason for this that anyone is aware of?

[quaidum]

i have noticed this as well with the coupe but my wagon doesn't seem to do it

[h22sparkle]

I've noticed this with every car I've ever driven. The first half tank goes forever. The second it hits the halfway point, it seems to head to E very quickly!

I just filled up my 10.6 gallon Fit tank. The needle was barely past 3/4, but I filled it with 4.2gal!

Is there any reason for this that anyone is aware of?

I think it is not because of the first half .I think it is because the prices. But you live in jersey, im sure it doesn't go up as much. There are alot of factors that affect that consumption,tune-up,spirited driving,driving up hills with stuff in in the car getting stuck in traffic.

[Ralphie]

The only two things I've come up with is-

The physics of the fuel system change as the fuel drops.

Its in our heads lol

[GhostAccord]

Could it be that the empty mark on the in dash gas gauge isn't marked where the tank is physically empty?????

[quaidum]

mine i will get 75-100 miles before it gets past the F

then i am at about 200 at 1/2 and close to 350 at just above E

i usually get about 340 miles at a 14 gallon fill up( i deliver pizzas in the city in the coupe which has been setup more for higher rpms)

[N9netwoAccord]

It is how the gas tank is designed. It may look like a simple basic shape, but it's designed to keep the fuel pump submerged in fluid almost all the time to help keep it cool.

[Skeet Skeet]

^^ this

The actually shape of the tank could be fat up top and skinny on the bottom.

[Chrisisiced]

As you use more gas there's also more room for the gas to splash around in the tank and give deceptive readings. Like if you're on a quarter tank and are hitting curves really hard your needle will read almost empty until you stop and sit still for a minute or so...

[Tippey764]

It's not in our heads

In my accord I can go 200 miles on the first half then 100 on the second half.

[Bullhorn7]

Gravity pulls the needle down harder as it falls past half

[fatboy1185]

Fuel gauges are not 100% accurate.

[Ralphie]

It's not in our heads

In my accord I can go 200 miles on the first half then 100 on the second half.

Right....which i think is due to the physics of the fuel system.

I can't sit here and explain it, but fuel viscosity and weight change due to temperature and as the fuel depleats, changes arise in the tank.

[foamypirate]

Fuel gauges are not 100% accurate.

This. I only believe my gauge at Full and 1/2. The rest is a crapshoot.

[mtnbikaah]

270-300 on the first half 125-200 on the second half.... I can gauge how well my tank is by what my mileage is at "half" tank....

Gravity pulls the needle down harder as it falls past half

at my high school there were some clocks like that. By half past the hour they were wicked fast, and sloooow by the time the top of the hour came around.... i guess they were accurate at quarter past and quarter of? LOL.