Gas Gauge Bars Unreliable?
 

In driving to work yesterday I left the house with ~450 miles on the clock and about a 45 mile trip to work (I usually fill around 500 miles). I had 4 bands on the fuel meter. A couple miles from work, while on a bridge in bumper to bumper traffic, the light came on and I had no bands :omg: :omg: :omg: :omg:

Over the next couple of miles poking along, the light went out and 3 bands reappeared. I was able to drive at least 10-15 miles with 3 bands to get gas. This has happened before, but dropped only to 1 band last time.

What's the deal? How can a deal with the accuracy of the guage at the bottom of the spectrum - where it matters most? :confused:

it varies
 

You saw an extreme variation, which is not usually the norm in my experience (10,200 miles so far on my 2004 HCH). I have found that I usually have about 1.5 gallons left in the tank when the "low fuel" light comes on. And that light sometimes comes on with three or two bars, never with 4 bars.

You are in good company. I've noticed that the fuel level is often underreported during idling, then increases when you step on the pedal.

No, no. When I left the house it was 4 bands, and 40 miles later 0 bands with the light on. When it went back to 3 bands (from 0!), the light was off. Sorry I wasn't more clear.

I haven't had enough tanks yet- but so far: low fuel light came on at 1 bar, drove about 20 miles and there was about 3/4 gallon left in my tank. haven't seen the bars flicker back and forth at all, but the other 2 times I refilled my tank at 1/4 tank/4 bars. I'm down to about there now, I'll keep an eye on it and post if I see anything weird going on- I was waiting for 1 bar anyway before I filled up.

You said you were on the bridge when it happened, where you on the incline or decline? I have had a few vehicle that did the same thing.
I have only been that low once on the HCH and it dropped about two bars while i was sitting on an incline to the bridge waiting to drive over and get gas.

Hopefully that is all yours was.
How much gas did the car take to fill up?

The float is usually at the front of the tank. If you're pointing downhill, the reading will go up, if you're pointing uphill, it will go down. I know for my 97 Civic the float must be at the front right side, because in a prolonged left hand turn (very long freeway transitions) the gauge will go up. On a prolonged right turn, the gas gauge goes down. The most accurate way to know is based on what it says your fuel economy is for that tank and how many miles since you filled up. Some quick math and that tells you how many gallons you've used.

Gas Gauge
 

Steve,
I've noticed this as well but don't have an explanation.
Once I drove to work of 46 miles & started off with 5 bands.
I parked with 3 left.
I started with 2 bars on.
Within a mile I was down to 1 bar and the fuel light on but still had about 45 miles to go and in a bad Atlanta neighborhood wanted to drive till the last one goes out, to a safer area.

(I hate how they place a giga-billion dollar business in these neighborhoods! Street dealers, ladies of trade, gunshots in the distance, right next to MARTA, Atlanta's "safe" public rail line)

I drove about 35 miles on that last bar before it went out, then filled with 11 point-something gallons of gas.

I remember once my wife & I started off near empty and after a mile or so 2-3 additional bars appeared.
She asked me why that happened and I simply replied:
"What do you expect, it's a hybrid car" (hee hee)

I've found the last 4-5 bars on the gauge to be less than reliable at times and in my case when the last bar goes out that's when I stop for fuel.

I think the computer seriously buffers the gas meter reading when the gas level is going up. It probably instantly calculates a low reading and displays it - so as to err on the side of saftey (i.e. you not running out of gas)...

BUT when it detects MORE fuel than the current reading, it waits a long time and gets multiple samples to ensure that this is correct (so it wouldn't behave like the example of AZCivc of going around a bend and showing a ton of fuel)

Here's how I came to that conclusion... I also experince the "almost instantaneous" drop in fuel bars every now and then (I live and work in a very hilly region). But today, when I filled the tank (12 gallons) and left the car on when it was filling (the engine was off ;) ) it took me about 8 miles of driving before the gauge finally read "full".

The whole time it was going up bar-by-bar; VERY slowly.

Re: Gas Gauge Bars Unreliable?
 

I think it was a slight incline. I was getting my best tank mileage ever, so even though I shouldn't have worried, I did.

Re: Gas Gauge Bars Unreliable?
 

That is definitely the opposite of my 97 Civic. I filled up today from what I consider a low tank (took 8.95 gal to top off; rated capacity of 11.9 gal) and once finished filling, I hopped in the car and put the key in the ignition and turned it to the "on" position. In the time it took me to write down my odometer mileage on the receipt and put the pen back in my glove box (apprx 15 sec) it had already completed a full sweep from just above the white "E" line to just shy of the top full line. My 97's fuel level indicator is very responsive, so yeah, if it took you 8 miles (10+ minutes??) there's a major difference they must have programmed in.

Re: Gas Gauge Bars Unreliable?
 

when my gas gauge gets down to four bars, it starts fluctuating according to how i drive. for example, i live on top of a large hill. when i go uphill to go home and start out with 4 bars, by the time i arrive at the top, the gauge reads 2 bars. The next morning, when i drive out again and go down the hill, by the bottom my gas gauge is reading 3 bars again, and when i'm on the highway after 5 minutes it goes to 4 bars again.

is it just me, or does the computer in the hch calculate the amount of gas remaining according to the instantaneous mileage you are getting when there are four bars or less of gas? it seems to me that it is trying to second guess the driver, because it magically increases the amount of gas when i'm coasting or braking, and decreases the amount of gas rapidly when i'm accelerating or going uphill for a short duration (<= 2700 rpm)

Re: Gas Gauge Bars Unreliable?
 

I get the feeling when I'm driving that it estimates fuel based on consumption. I don't know if there is anything to it.

Re: Gas Gauge Bars Unreliable?
 

This weekend, I had three bars reappear after I had no bars and the gas light came on. I didn't want to risk it, even though I had 3 bars. Well, I filled up with 11.9 gallons. I had about 15 miles left before I ran out of gas, even though I showed 3 bars. I would recommend getting gas with 3 bars or less left.

Re: Gas Gauge Bars Unreliable?
 

Sorry, I mistyped. I thought the tank held 12.2, not 13.2. An any case, those bars are messed up. You can't trust them, trust your total miles driven based on your calculated mpg.

Re: Gas Gauge Bars Unreliable?
 

Briefly commenting on jahwerx's post... this very thing happened to me with my '01 Accord V6, which had an analog gauge. So I don't think it's necessarily something 'hybrid-related' or '-designed', but I do think it's prevalent on Hondas (at least 2 late model platforms that we know of). At the time it happened, it was very disconcerting - I thought I had broken the gauge. But in a few miles, it had climbed back to the full mark.

Ok...I'm going back to bug the HAH owners now... :angel:

Re: Gas Gauge Bars Unreliable?
 

I do dealer transfers for a Honda dealership and have occasion to drive most all of the Hondas. I have found that there is something funny about the Civic gas gauges. For some reason they fluctuate at times. I put gas in a HCH and it took a couple of miles or so before the guage indicated a change, made me wonder if the pump put any gas in the car. Similar situations with the regular Civic. Must have to do with the float or whatever they use to gauge the fuel level. I am waiting for my HCH to arrive at dealer, will be reporting my experience with it soon.

Re: Gas Gauge Bars Unreliable?
 

the float explanation makes sense

i wish the gas gauge could tell you exactly how many gallons are remaining in the tank. this way would be much more accurate than trying to guess using the distance recorded on the trip odometer and the average mpg for the tank.