Gas tank capacity issue

[Proprioceptive]

We just bought a 2007 Hyundai Entourage with 39k miles on it. Everything runs smoothly and we love it, but I noticed something strange the other day. The MPG is kind of low and when I went to fill it up... I waited until it actually hit E... I only got 15.5 gallons in the tank before it stopped. According to documentation, this vehicle has a 21.1 gallon tank. I asked the service guys at the Hyundai dealership (different dealership than where purchased), and they said it is probably because there is really a "reserve" of gas when it hits E so you don't really run out of gas... but 6 gallons of reserve?? Is this normal? I'm having it taken in on Friday just to make sure and have them take a good look at it.

 

[Zenmervolt]

It's a combination of probably having between 2 and 3 gallons of reserve left when the gauge is on "E" and the fact that gas pumps are calibrated to shut off before the tank is completely full. As the tanks in cars are increasingly form-fitted to the cars, this also means that many vehicles are sensitive to orientation (i.e. which way the car is sloping or leaning) when filling the fuel tank which can limit the ability to fill the tank to its rated capacity. Additionally, most cars have their fuel gauges programmed to read "full" for several gallons, so even if you're two gallons shy of a truly full tank, the gauge will still read "full".

ZV

 

[LTC8K6]

Did you wait until it says it's low on fuel, low fuel light/warning?

Gauges aren't all that accurate.

 

[LTC8K6]

Yeah, did you just let the pump stop once and quit, or did you wait a bit and try to pump more?

 

[Proprioceptive]

I waited about 50 miles past the low fuel light, and no, I stopped filling when the pump stopped. Maybe I'll try putting more in after a few minutes and see what happens. The other problem is that according to Hyundai and other consumer websites, this van should get about 330 miles on the low end per tank, whereas my low fuel indicator came on at 220 miles and I filled up at 270 miles... and I was even doing mostly highway at that. I hope there's nothing wrong with it.

 

[PlasmaBomb]

17.5 MPG ouch

 

[LTC8K6]

Why in the world would anyone go 50 more miles after the low fuel light came on? Is your name Kramer?

 

[Proprioceptive]

Originally posted by: LTC8K6
Why in the world would anyone go 50 more miles after the low fuel light came on? Is your name Kramer?

It goes on kind of early in our van... wasn't quite at E yet. I carry extra gas with me anyways, just in case.

 

[TraumaRN]

Originally posted by: LTC8K6
Why in the world would anyone go 50 more miles after the low fuel light came on? Is your name Kramer?

I drove for almost 50 miles past E on my Fusion Hybrid. Filled it with 15.95 gallons of gas. Tank is 17.5 gallons. I trust my 'reserve.' And anyways that tank was only 761 miles. I'll be pushing 850 on this current tank before I fill up.

 

[LTC8K6]

Man, I never run that low. Always fear for my fuel pump.

 

[PlasmaBomb]

Originally posted by: DeathBUA

Originally posted by: LTC8K6
Why in the world would anyone go 50 more miles after the low fuel light came on? Is your name Kramer?

I drove for almost 50 miles past E on my Fusion Hybrid. Filled it with 15.95 gallons of gas. Tank is 17.5 gallons. I trust my 'reserve.' And anyways that tank was only 761 miles. I'll be pushing 850 on this current tank before I fill up.

Cool. Post the fuel economy when you fill up.

 

[vshah]

Originally posted by: DeathBUA

Originally posted by: LTC8K6
Why in the world would anyone go 50 more miles after the low fuel light came on? Is your name Kramer?

I drove for almost 50 miles past E on my Fusion Hybrid. Filled it with 15.95 gallons of gas. Tank is 17.5 gallons. I trust my 'reserve.' And anyways that tank was only 761 miles. I'll be pushing 850 on this current tank before I fill up.

47 mpg, that is seriously awesome...

 

[TraumaRN]

Originally posted by: vshah

Originally posted by: DeathBUA

Originally posted by: LTC8K6
Why in the world would anyone go 50 more miles after the low fuel light came on? Is your name Kramer?

I drove for almost 50 miles past E on my Fusion Hybrid. Filled it with 15.95 gallons of gas. Tank is 17.5 gallons. I trust my 'reserve.' And anyways that tank was only 761 miles. I'll be pushing 850 on this current tank before I fill up.

47 mpg, that is seriously awesome...

This current tank is going to be even better. I'm on track right now for close to 850 miles which would be 50+ mpg in a car rated for 41city/36highway.

 

[Black88GTA]

Originally posted by: Proprioceptive
We just bought a 2007 Hyundai Entourage with 39k miles on it. Everything runs smoothly and we love it, but I noticed something strange the other day. The MPG is kind of low and when I went to fill it up... I waited until it actually hit E... I only got 15.5 gallons in the tank before it stopped. According to documentation, this vehicle has a 21.1 gallon tank. I asked the service guys at the Hyundai dealership (different dealership than where purchased), and they said it is probably because there is really a "reserve" of gas when it hits E so you don't really run out of gas... but 6 gallons of reserve?? Is this normal? I'm having it taken in on Friday just to make sure and have them take a good look at it.

My Subaru has about 6 gallons of reserve. It has a notoriously pessimistic fuel gauge.

Fillups are usually 11-12 gallons, the tank holds around 18 I think. I fill up when the needle hits E. Fine by me, as I don't really like running the tank down below 1/3 of capacity anyway.

 

[LTC8K6]

I drove for almost 50 miles past E on my Fusion Hybrid.

Not really relevant since your Fusion does not swill gasoline at the rate an Entourage does.

That 50 miles in the Entourage would have consumed nearly 3 gallons of fuel. Much bigger risk.

 

[angry hampster]

Originally posted by: LTC8K6
Man, I never run that low. Always fear for my fuel pump.

Same here. I never let mine run below 1/4 tank just so I can make sure the pump is staying cool.

 

[radioouman]

I usually drive 60 miles past when my fuel light comes on in my Dakota. I do this all the time.
But there is a chance that the vent on your tank isn't working, and the fuel pump has collapsed the inner bladder inside the fuel tank. The fuel pump causes a vacuum inside the tank and if the vent isn't working, it will collapse the bladder.

 

[LTC8K6]

I usually drive 60 miles past when my fuel light comes on in my Dakota. I do this all the time.

Well, it's your fuel pump.