From the HCH II owner's manual:

"When the (low fuel) indicator comes on, there is about 0.9 US gal of fuel remaining in the tank before the reading reaches E. There is a small reserve of fuel remaining in the tank when the reading does reach E."

In my 2-week-old HCH, the low fuel light came on yesterday. 25 miles later, the last two lights on the digital fuel guage went dark.

Within 10 more miles, I pulled into a gas station, but could only get 10.8 gallons into the tank -- standard fill, then two clicks after that.

I know that I have the 12.3 gallon tank, because I got under the car and checked. It's the factory plastic one, as opposed to the California metal one that only holds 11 gallons.

So that means that the HCH has 1.5 gallons remaining in the tank AFTER all the lights go out on the fuel guage. That's 60 miles or more!

Certainly not "Empty."

 

California metal one that only holds 11 gallons? Where did you hear that? I've put in 11.5 in mine

 

Yeah, but you got to think they design it this way so us idiots don't decide to take it to dry, thinking we can pull into the gas station at the last moment- only to realize that we left our wallet at home. Anyways, if you record your mileage on an ongoing basis, it doesn't matter if you take the tank to empty- it's all about your total FE.
Just my 2 bits.

 

(I originally posted this in the Accord thread, but it applies here also.)

Because of the mechanics of how a typical fuel guage sending unit works, (a float in the tank), it will always be inaccurate at both extremes of measuring a tank volume.

For example:

Full tank. The top of the float is pinned against the upper part of the tank and doesn't move, (because it is not floating), until some portion of the tank is burned off. The guage thus reads full longer than is real.

Empty tank. The bottom of the float comes to rest against the lower surface of the tank and cannot move further, (because it is not floating), even though there is still fuel in the tank to burn. The guage therefore reads empty but you still have gas.

howstuffworks.com has a good demo of this.

 

What a timely post! I'm shooting for my first 600 mile tank, and I've gone about 12 miles on the last bar (empty light is on, still showing 1 bar of fuel left). I'm currently sitting at 588 miles @ 55.6mpg, so I figure I'm pretty safe to drive to at least 600 miles before my next fill.

I've driven to 0 bars before and the most I've ever put in the car was just under 11 gallons. So I figure I probably should have been able to go another 50-80 miles even in that case. I don't know enough abou engines and fuel injectors to know why it's bad to run out of gas, but I've always heard it's not good for the car, regardless of the resulting interstate hike. I'm assuming I have the 12.3 gallon version since I bought the car new in North Carolina.

 

In my view the worst thing about running out of gas is the safety issue surrounding the process of getting fuel to and in the vehicle. Most cars now have the fuel cap on the driver's side meaning that you may be in harm's way of proximity to traffic and being hit by an oncoming vehicle. This is one of the main reasons that police have such a dangerous job - not gunplay as is commonly thought.

Mechanically speaking, I avoid getting too low on the tank and therefore unnecessary sucking of the sludge, (moisture, rust, chewing gum, whatever), that is normal to reside in the lowest portions of the tank usually below the intake for the fuel pump. This sludge can and will clog the fuel filter and find its way to the injectors. ( On a side note very occasionally a manufacturer provides a total tank volume and a useable tank volume - the difference being the part below the fuel intake. I don't know about the Civic but assume that the volume in the specs is the useable volume.)

Often, including on this site, posters claim that the fuel in the tank also cools the fuel pump and that going too low on the tank can cause damage to it, (the pump). I think that this is unlikely due to the obvious potential for a catastrophic safety problem - aka - the tank, car, and driver explode. Since exploding cars are rare outside of Hollywood and folks run out of gas all the time, I say cooling if required at all is not provided by fuel in the tank.

 

You'd think that after all these years someone would have come up with a more accurate (e.g., electronic) method to measure fuel level.