Gas tank mystery solved.

[Mike1357]

This may have been covered elsewhere before, but with so many threads as old as they are, it would be pointless to bump them from the dead.

Essentially, according to all accounts, our gas tanks have a capacity of 17 gallons. What most assume is that that figure means they can fill the tank to 17 gallons of gas; this is not the case. The measurement of 17 gallons is basically just the internal volume of the tank itself.

The reason you cannot fill the gas tank more than ~14 gallons is due to the manufacturers of gas tanks making the tank in such a way that the tanks can only be filled with gasoline to about 80% of the total volume to account for vapor expansions due to temperature differences.

Boom.

[RyanD]

Thanks for that! Now i know why!

[Straight Success]

I've filled mine to 16+ gallons. I'm pretty sure.

[dysfunk]

This would explain why I have never put any more than 14.6 gallons in my tank. And I thought I was the weird one.. Haha. Good deal, dude.

[H311RA151N]

Good info!

[oyajicool]

The difference is the total tank capacity and usable capacity.

Due the shape of upper surface of the tank, there is an area/space which, by design, cannot be filled with fuel. Yes.

I estimate it to be between one to two gallons, by the looks of it.

There's other thing to note is that there's certain amount of fuel that cannot be sucked by the pump, which is called un-usable fuel. Due to the shape of lower surface of the tank along with the location/height of fuel pick-up point, this dead capacity of fuel do exists.

I guess-timate it to be one to two gallons as well.

Combining above two makes re-fill fuel quantity to be less than total tank capacity.

[drew12000]

I've filled mine to 16+ gallons. I'm pretty sure.

[oyajicool]

He could have been running on fume before fill up.

[Straight Success]

My orange light was on for a day almost. i drove back and forth to school like that. As a matter of fact, it happened right before my motor went. After draining about two gallons out of it, I still have about 7/8 tank left in my undrivable car at the moment.

[Fleetw00d]

I pushed my wagon a little too far once, it died in a long curving highway on ramp. I was able to coast to the next exit (~0.5 miles, slightly downhill). It restarted at the bottom of the ramp. Fill up was 15.3 gallons.

[Losiracer2]

I've put in 15.5 gal in my coupe and consistently put in about 14.5gal in my sedan on every fill up.

[RyanD]

He could have been running on fume before fill up.

fuel pumps can pump air?

[GeoffM]

Looking through my car tracker:
15.17
15.23
15.56
15.02
15.91
17 (I think that's when I ran out of gas)
15.01
15.24
15.22
15.64
15.08
15.22
15.02

There are plenty of others, I just wanted to post the 15+ records.

[oyajicool]

fuel pumps can pump air?

I'm sure it could. But engines won't run on fume. We all should know that.

It's a hangar joke/saying around here at the airport.

[RyanD]

I'm sure it could. But engines won't run on fume. We all should know that.

It's a hangar joke/saying around here at the airport.

i know, i was being a smartass