Fuel Gauge question

[Moonpennies]

Here's my question: Our P5's gas tank holds 14.5 gallons. My fuel gauge needle is practically on the 'empty' line when I fill up, but it will only take about 12.5 gallons (which of course means I have approx 2 gallons left in the tank. ) Is there a light that comes on in the dash when we get close to empty? Anyone ever run out of gas? Just wondering.

 

[Sir Nuke]

Here's my question: Our P5's gas tank holds 14.5 gallons. My fuel gauge needle is practically on the 'empty' line when I fill up, but it will only take about 12.5 gallons (which of course means I have approx 2 gallons left in the tank. ) Is there a light that comes on in the dash when we get close to empty? Anyone ever run out of gas? Just wondering.

No, never run out of gass in my P-5....and YES there is a light...and its ON your gas gauge. look just above the little gas pump symbol and you will see a little round spot....well that is the light....when it comes on its orange. What I did was when I FIRST got my car I ran it till the light came on just so I would know how much was left when the warning light came on...in MY car I have right at 2 gallons left when the light comes on.

 

[Red Baron]

And you can still pump in a good amount of gasoline after the thing clicks off. In my case, I'm able to pump 5 litres more (about 1.5 US galon). Takes around 100k (62 miles) before the needle starts going down.

 

[fastdrvr23]

Here's my question: Our P5's gas tank holds 14.5 gallons. My fuel gauge needle is practically on the 'empty' line when I fill up, but it will only take about 12.5 gallons (which of course means I have approx 2 gallons left in the tank. ) Is there a light that comes on in the dash when we get close to empty? Anyone ever run out of gas? Just wondering.

Hmmm, I drove about 65 miles after the fuel light came on, but I didn't run out of gas... I pumped 14.2 gallons in so I was close..

I have noticed the gauge readings as well. On empty when the fuel light just starts to flicker I have ~2 gallons to go.

 

[Don]

And you can still pump in a good amount of gasoline after the thing clicks off. In my case, I'm able to pump 5 litres more (about 1.5 US galon). Takes around 100k (62 miles) before the needle starts going down.

It DOES take quite a bit of effort to get it really "FULL"

When mine is full, I go 90 miles before the gauge starts to move.

I made an even 450 miles on one tank while we were on vacation, and it took 14.3 to "fill" it up, so I guess I was pretty close to the bottom.

You can usually do another 50 miles easy, once the little light comes on.

Don

 

[Moonpennies]

Thanks guys, you've ansered my questions! I won't worry so much when I see the needle on empty, I'll look for the light.....

Hey Sir Nuke, in a past posting I was asking questions about the 5 spd, I wasn't sure if I should get the 5 spd or automatic. You were right, I love the 5 spd! The stop & go traffic is a pain, but all the other driving makes up for it. THANKS.

 

[Sir Nuke]

Thanks guys, you've ansered my questions! I won't worry so much when I see the needle on empty, I'll look for the light.....

Hey Sir Nuke, in a past posting I was asking questions about the 5 spd, I wasn't sure if I should get the 5 spd or automatic. You were right, I love the 5 spd! The stop & go traffic is a pain, but all the other driving makes up for it. THANKS.

Moon, YOU are more than welcome....I KNEW you wouldn't be disappointed with that choice. :{D

 

[ZiO]

Personally I think ou shouldnt let the car go past 1/4. I know from previous vehicles, espescially Fords, have their fuel pump mounted inside the gas tank.... past 1/4 starts to burn out the pump...... its better to have the pump submerged in fuel rather than letting it sit in empty vapours and pumping fuel.

But of course its up to you... but i have seen MANY cars getting their fuel pumps replaced within 6 or 7 years for simply that reason.

 

[LambOfSilence]

Zio just stole my thunder , I think it is a good idea to keep above 1/4 as well, just think where the dirt and other unpure stuff in the fuel will go, to the bottom.

On the other hand, however, I am a very lazy person, always wait till the last moment, 50km after the light comes on.

Going to make the 1/4 fill-up my habit now.

 

[njaremka]

Zio just stole my thunder , I think it is a good idea to keep above 1/4 as well, just think where the dirt and other unpure stuff in the fuel will go, to the bottom.

where do you think the fuel pick-up is? at the top? if there is dirt and scum in your tank, and it settles to the bottom... if there is dirt and scum in your fuel tank, there is a filter screen on the pump that keeps the stuff that would harm the pump out, and the rest gets filtered by the filter!

Personally I think ou shouldnt let the car go past 1/4. I know from previous vehicles, espescially Fords, have their fuel pump mounted inside the gas tank.... past 1/4 starts to burn out the pump...... its better to have the pump submerged in fuel rather than letting it sit in empty vapours and pumping fuel.

But of course its up to you... but i have seen MANY cars getting their fuel pumps replaced within 6 or 7 years for simply that reason.

yes, the pump is in the tank, just like 99% of other cars out there. however, replacing a fuel pump after 6-7 years I would think would be a good thing any way. of course, that's me.

 

[Moonpennies]

That 1/4 tank thing is interesting. My gas seems to get used up quicker on the last quarter tank. But, that's probably because the gauge shows 'empty' when there's really 2 gallons left. I just replaced my fuel pump in my BMW (I'm trying to sell it now that I have my P5) and the dumb pump was $650.00! Beemers are extremely expensive to fix. I won't go that route again.

 

[LambOfSilence]

njaremka, oh ya~, good point, was not thinking clearly I guess

 

[BondoBob]

The mention of fuel and BMWs sparked (!) a memory. My high school/post high school girlfriend would put a buck or two of gas in my BMW 1600 when she drove it (if she ran it down to 'no gas'). This meant that the car would be bone #$%! dry when I would hop in, meaning that I would have to drive to a gas station and FILL IT UP before going someplace. (She did this in HER car, too, so it wasn't a spite thing.)

To this day, except for a long trip, I keep at least a quarter of a tank of gas in the car.

 

[Red Baron]

Tank, no less

And if you live up here in the Great White North, going under a tank during winter is asking for trouble...

 

[Don]

That 1/4 tank thing is interesting. My gas seems to get used up quicker on the last quarter tank.

The fuel gauge isn't linear because the tank isn't a perfect rectangle. The gas gauge just measures how far down in the tank the float is. On the P5, about 2/3rds of the total capacity is in the first 1/2 of the gas gauge indication. The "last half" is really more like the "last third."

Don

 

[blynzoo]

The fuel gauge isn't linear because the tank isn't a perfect rectangle. The gas gauge just measures how far down in the tank the float is. On the P5, about 2/3rds of the total capacity is in the first 1/2 of the gas gauge indication. The "last half" is really more like the "last third."

Don

Damn Don, you beat me to it. I was just about to say that.

 

[ZiO]

NJAREMKA.. not ALL cars have the fuel pump in the tank.especially older vehicles which had fuel pumps in the front of the engine... pump work better pulling the fuel to the engine rather than pushing it.. do some homework before you act like a superman... people like you shouldnt respond. And if you want to buy a pump every couple of years, thats your stupid decision. Why replace it in 6 years if its good enough for 15 or more.

 

[Don]

Actually, nearly any pump works better "pushing" rather than "pulling" - Pumps used to be in the front because they were mechanical, and driven off the engine.

Once they moved on to electric pumps, they were usually mounted in the rear, near the gas tank so that they could "push."

When fuel injection came along (which requires a much higher pressure pump) they began mounting them inside the tank, so the liquid could cool the pump, and that supposedly gives them a longer lifespan.

I doubt that anyone will notice the difference in pump lifespan between always running with 1/4 tank or more versus those of us who frequently let the tank run pretty "dry" before we fill it up though. I'm one of the "dry" guys, and in the last several hundred thousand miles, I've never had to replace a tank mounted pump - I've put well over 150K on 3 or 4 of them too . . .

Don

 

[ZiO]

You just agreed to what i said..

When fuel injection came along (which requires a much higher pressure pump) they began mounting them inside the tank, so the liquid could cool the pump, and that supposedly gives them a longer lifespan.

.... and i have seena longer life span, since i have had cars since 77..... and the oldie gas pump.. especially in that 77 buick of mine, has lasted for 22 years before it got replaced. No tot mention my 79 Suburban, which i still have since new, has had only the radiator replaced since i've had it.


Thank You.

 

[Red Baron]

The fuel gauge isn't linear because the tank isn't a perfect rectangle. The gas gauge just measures how far down in the tank the float is. On the P5, about 2/3rds of the total capacity is in the first 1/2 of the gas gauge indication. The "last half" is really more like the "last third."

Don

I also noticed that in my last 2 cars (both Civics). Why the hell can't they use some kind of sensor in the fuel line that measures the amout of gasoline that goes by? Another sensor could be used to tell initial quantity at fill-up (say, when you press the Trip button, it takes a reading). A simple computer could do the math...

A friend of mine is an Engineer in Data Aquisition, I should ask him (see www.isaacinstruments.com).