bigfool0724

Hey guys, Ive been noticing the past few weeks that when I commute on the freeway, after im done it the gas level will be at a certain level. But when I come back and start it up again like an hour or so later, the gas level is significantly lower than when I left it! Is this something that's supposed to happen?

ZeroSeVen

how significant is the drop in your fuel gauge?

Do you park your cark on an even surface?

The sensing unit that is located in your gas tank uses a float connected to a potentiometer. As the gas volume in the tank decreases, the float mechanism drops and slides a moving contact along a resistor, increasing it's resistance which then sends signals to your dashboard. How your car is parked may affect the float in your gas tank.

kirillbenz22

my gas gauge is broken and have been it always drops up and down irregularly completely ****ed i ran out of gas 2wice becuase of that problem haven't had time to fix it yet plus I usually write down my millage just to make sure

bigfool0724

Yes my car is def on an even surface. Usually it drops by 1/16 of a tank or so. I just started noticing because I've been trying to save on gas lately and checking the fuel all the time. As for parking, even if I did park on a hill or something, it should have evened out on a flat surface right?? I'm just trying to see if others have noticed a drop in their gas like mine.

ZeroSeVen

I haven't notice any significant drop on my fuel gauge after I park and restart my car... I suggest to calculate your gas mileage/ distance driven from the time you fill your tank to the point where the low fuel alert comes on, If it's considerable less to what you had in the past then I think there may be a problem

bigfool0724

Well for the past week, ive only driven to school and back. My school is exactly 20 miles from my house (according to my dash) so that means ive been doing 40 miles a day. I know 1/16 doesnt sound like much but it adds up really quickly for each trip -_-'. It sucks to come out of class or wake up to find that gas automagically somehow disappears from your car haha

Carsy

If your MPG is OK then why worry.

bigfool0724

Its not gas that's being wasted while on the road but rather while its sitting still. Wouldn't that strike you as a bit odd if it were you? lol

Carsy

No. I would accept that it is a characteristic of the guage or fuel tank & would think it was highly unlikely that I was loosing fuel.

1/16 of your fuel tank amounts to over 4 litres . You would notice it if there was a leak.

If there are no puddles under the car or fuel smell in, under the bonnet or around the car then there is not a leak.

Possible explanations , some previously mentioned include, cooling & contraction of the fuel, cooling of the sensor therefore a different electronic resistance to guage,more pressure in fuel tank after sitting making tank expand .ie maybe a slight vacuum in tank when operational.

If you continue to be concerned mention it to your MB tech .

Good luck.

C300Sport

I had a Nissan 240 that would seem to gain an 1/8 whenever I parked her after longer uninterupted trips. Funny, but it almost made me feel like I had a little gas gnomes filling my tank...would have been nice but alas....

bigfool0724

Hmmm I didnt think about the contraction of fuel... thats something to def keep in mind. I'll keep watching my fuel guage and calculate to see if I'm actually losing anything.