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Yeah, yeah, yeah, I hate to be the starter of another "does your car do this?" post, but...

I've noticed that when my car is down to 1/8 of a tank or so, the 'range' indicated on the computer when I start it up in the morning drops rather significantly in comparison to what it was showing when I parked it the night before. hmmm After driving for a couple of miles the range increases back to approx where it should be. I don't know if this is some sort of quirk in the range calculations or what? Am I alone here, or are other m's drinking from their gastanks while we sleep?

Oh, by the way, no - no one else has access to the car.
 

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Murph said:
Yeah, yeah, yeah, I hate to be the starter of another "does your car do this?" post, but...

I've noticed that when my car is down to 1/8 of a tank or so, the 'range' indicated on the computer when I start it up in the morning drops rather significantly in comparison to what it was showing when I parked it the night before. hmmm After driving for a couple of miles the range increases back to approx where it should be. I don't know if this is some sort of quirk in the range calculations or what? Am I alone here, or are other m's drinking from their gastanks while we sleep?

Oh, by the way, no - no one else has access to the car.
I have noticed this also. I believe the computer is tied to the miles per gallon computation in the computer. So as you drive, it gets a better of idea of your gas mileage vs. when you start up and aren't going anywhere and using gas.
 

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Murph said:
Yeah, yeah, yeah, I hate to be the starter of another "does your car do this?" post, but...

I've noticed that when my car is down to 1/8 of a tank or so, the 'range' indicated on the computer when I start it up in the morning drops rather significantly in comparison to what it was showing when I parked it the night before. hmmm After driving for a couple of miles the range increases back to approx where it should be. I don't know if this is some sort of quirk in the range calculations or what? Am I alone here, or are other m's drinking from their gastanks while we sleep?

Oh, by the way, no - no one else has access to the car.

Yep, I can drive in at night with a 1/8 or more of a tank and come out in the morning with the orange light on looking like I am empty. I almost thought someone was siphoning. hmmm
 

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Murph said:
I've noticed that when my car is down to 1/8 of a tank or so, the 'range' indicated on the computer when I start it up in the morning drops rather significantly in comparison to what it was showing when I parked it the night before. hmmm After driving for a couple of miles the range increases back to approx where it should be. I don't know if this is some sort of quirk in the range calculations or what? Am I alone here, or are other m's drinking from their gastanks while we sleep?

Oh, by the way, no - no one else has access to the car.
Same here - but it's not just the range it's also the fuel gauge reading lower on initial start up and then coming back up some after a few miles of driving. This is especially noticable if you are close to the low fuel lamp illuminating - it will light up at start up and then go out after a few miles of driving.
 

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My 00 does the same thing. It is always different in the morning. But it usually goes back to where it was the night before after a couple of miles of driving. I think the resistance of the fuel gauge changes a bit as the temperture get cooler at night.


Joe
 

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Murph said:
Yeah, yeah, yeah, I hate to be the starter of another "does your car do this?" post, but...

I've noticed that when my car is down to 1/8 of a tank or so, the 'range' indicated on the computer when I start it up in the morning drops rather significantly in comparison to what it was showing when I parked it the night before. hmmm After driving for a couple of miles the range increases back to approx where it should be. I don't know if this is some sort of quirk in the range calculations or what? Am I alone here, or are other m's drinking from their gastanks while we sleep?

Oh, by the way, no - no one else has access to the car.
Mine too, but I put it down to the auto choke being used first thing in the morning, the car idles at a lot higher speed whilst it is warming up. Once warm it settles back down and the mileage left reading reverts to the level of the night before.

This caught me out a few times in that I've put the car in the garage at night with about 25-30 miles on the read out and in the morning it reads 0 !! When my mechanic pulled the SES codes recently (after that dammed yellow light came on )one of them was something like " Error occured with empty fuel tank". He reset the light and all was well again. I didn't lose any performance but just that yellow light on raised the heart rate a little bit just in case it was something that was going to cost....:eek:h:
 

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This apparently is a design "feature". In a thread about how to unlock the OBC, there was a note that there seemed to be two indications for fuel, a rising number and a declining number that were combined. It seems the reading is designed to be lower when starting up (why? only those German engineers seems to know! :eek: ), so I don't think there is anything wrong with the gauges.
Regards,
Jerry
 

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Interesting that there is a technical reason -- I had simply put it down to my garage floor sloping slightly outwards plus the tires cooling down, therefore the car sitting at a different angle creating a different fuel reading !

It's amazing how your mind can rationalize many things.
 

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hudson said:
I think the resistance of the fuel gauge changes a bit as the temperture get cooler at night. Joe
Not really, but the denisty of the fuel does change with temperture changes. This can also affect amount of fuel you add from time to time when the gauge shows low.
Luckily, the density of bier stays relatively constant, just don't drink as much in the winter cherrsagai
Ken
 

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gsfent said:
This apparently is a design "feature". In a thread about how to unlock the OBC, there was a note that there seemed to be two indications for fuel, a rising number and a declining number that were combined. It seems the reading is designed to be lower when starting up (why? only those German engineers seems to know! :eek: ), so I don't think there is anything wrong with the gauges.
Regards,
Jerry
Makes sense - there are 2 level sending units in the fuel tank. The final fuel level "reading" is a combination of the 2 and it could be that the software needs some minimum amount of time to arrive at the final level reading. In the interim it errs on the side of showing too low as opposed to showing too much fuel.
 

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I as well see this just about every week when the gas gets toward empty, I guess this must be normal if everyones else does it as well, has anybody had this happen? Once I was almost empty and I filled the tank up to the brim, almost overflowing, I was going on a road trip and wanted to see just how far I could get on a tank of gas, and when I turned the car on after fuleing the fuel gage only registered a 1/4 of a tank, it didnt begin sensing properly until I burned the fuel down to the quarter tank level, it has only happened once, but now just quit fueling when it clicks instead of pumping a little after, Josh
 

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bmwusa said:
I as well see this just about every week when the gas gets toward empty, I guess this must be normal if everyones else does it as well, has anybody had this happen? Once I was almost empty and I filled the tank up to the brim, almost overflowing, I was going on a road trip and wanted to see just how far I could get on a tank of gas, and when I turned the car on after fuleing the fuel gage only registered a 1/4 of a tank, it didnt begin sensing properly until I burned the fuel down to the quarter tank level, it has only happened once, but now just quit fueling when it clicks instead of pumping a little after, Josh
I have run my car well into the reserve. On a recent trip I watched the gauge as well as Range. When I got down to about 20 miles, I refueled and put in 19 gallons in an 18.5 gallon tank!(I attribute difference to filler neck, but I still had almost 1 usable gallon if the Range reading was correct). I also find the yellow reserve light comes on way too early, but if that turns out to be my biggest complaint I can live with it :haha: .
Regards,
Jerry
 
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