Fuel guage difference after overnight?

[ChrisGTL]

Anyone else notice this? Or is it just me?

I filled up yesterday, and did 80 miles - fuel guage was just starting to drop from full mark.

Parked car up last night after doing my 80 miles and there is slept overnight.

Come to using the car this morning and now the fuel guage is about 2mm above 3/4 mark, certainly not where it was when I left it last night.

My drive is very flat (I get standing water when it rains so it must be pretty flat), this is not the 1st time i've noticed this, but wanted to make sure it does do it before making a thread.

Is there something that heats the diesel up before it goes to the injectors? Could my heater be heating the fuel up too much and its evapourating away somehow?

Very strange......when I start my car in a morning I get a line of black crap on my paving blocks from my exhaust, happens for a split second then I just get the normal white moisture smoke.

Any views?

 

[ChrisGTL]

Come on! Who is pinching my fuel while I sleep?

U buggers!

 

[brad1]

"Im nicking your fuel"

only joking mate, ive never had this happen to me, but sometimes when for example after putting fuel in my car and lierally jus driving away from fuel station, the needle will move down slightly. (if filled up and turn the ignition on, needle moves to half, it will drop slightly off as i drive away, maybe this is the fuel settling, but not sure on your one mate

 

[jonjay]

The needle adjusts to your driving style. If you are averaging 30mpg instead of 50mpg then it will drastically drop.

As for the exhaust it is probably where moisture has built up and when you switch on the car its sort of coughed out the residue.

The cold brings out paranoia hehehe.

 

[brad1]

The cold brings out paranoia hehehe.

every winter i bet this forum gets tons of threads where people are worrying their turbo is on the way out when chucking out white smoke on start up

 

[Viking]

The fuel heats up as you're driving, and heat makes the fuel expand in volume so there's more of it in the tank. So when you drive home and see a full (nearly) fuel gauge when you park up, you're seeing fuel at a reasonably warm temperature. Overnight it'll cool down to near freezing point and there is then less volume of fuel compared to the night before. If you watch closely, you can drive for a good few miles with little or no change in the fuel gauge as the fuel expands with the heat again.

 

[ChrisGTL]

The fuel heats up as you're driving, and heat makes the fuel expand in volume so there's more of it in the tank. So when you drive home and see a full (nearly) fuel gauge when you park up, you're seeing fuel at a reasonably warm temperature. Overnight it'll cool down to near freezing point and there is then less volume of fuel compared to the night before. If you watch closely, you can drive for a good few miles with little or no change in the fuel gauge as the fuel expands with the heat again.

Spot on!!

Never thought of it like that

.......and relax

 

[basssound]

Also fuel contracts in freezing conditions!

 

[Robb1990]

Mine goes up, if i top up my usual weekly amount, i'll get to the mark past half way, then i turn off/re-start the needle will move up, sometimes to 3/4 mark, but not allways, usually between the two.

 

[RobTheHood]

Just my 2 pence worth, I don't see this happening to my gauge. It does drain erractically ie stays at top for 80 miles then drops like a bomb to half way (after another 150 miles or so) and then slows again as if mpg has improved, but trust me my consumption is fairly constant bar unforseen traffic jams. I'll take more notice to see if mine does it but I don't think so.

 

[sssstew]

Chris - if your only getting 80 before it moves, are you not venting?

 

[JamesL]

I dont bother venting - I cant see it making that much difference.

I get nearly 100 miles from the first 1/8th, 150 by the 1/4 mark, 250 by the 1/2, then fill up between 400 (3/4) and 450 (7/8ths).

Presume thats just the fact that the tank is a funny shape!

 

[jcc-gttdi150]

My car does this too mate.

 

[nad_84]

Also fuel contracts in freezing conditions!

Good point! Make sure when you're filling your car up, that you do it on a very cold night, the fuel is denser...meaning you get more diesel for your money take that BP + Shell + blah blah blah

 

[ChrisGTL]

Chris - if your only getting 80 before it moves, are you not venting?

I dont vent mate.

I let it click off, wait 5 seconds for bubbles to settle and fill till it stops again.

 

[Husbandofstinky]

Make sure when you're filling your car up, that you do it on a very cold night, the fuel is denser...

Heard this one before.

 

[jabbasport]

Exactlly what i was going to say regarding fuel density...

My car feels so sluggish untill the fuel has warmed up...

 

[Robb1990]

diesel thickens up when its cold, that's why its sluggish, as it doesn't burn quite as well.