I always thought that you get better gas milage?

Question

if you fill up your tank. A friend of mine made a good point. Don't do it because the weight will drag the vehicle down. It's best to fill to a quarter or half at a time because it's lighter. Is he right?

Answer 1

It's actually better for the car to not have it drop below 1/4 tank, and the weight of the gas won't affect your performance or efficiency

Answer 2

No,how heavy can fuel be anyway?

Answer 3

This makes little sense.  The average tank is somewhere between 15 -20 gallons, and this weighs less than a person.  Fuel in your vehicle is necessary weight, unlike if you have a trunk loaded with junk.  Engineers take into consideration the weight of a car with a full tank of fuel.  It is hard to believe that if an engine can't overcome 3000+ pounds of machinery that it cannot handle less than 100 pounds of fuel.  This is like saying you are not going to eat because of the risk of gaining weight, but you need food for fuel.

Answer 4

true, but in a stock car.

Answer 5

Unless your gas tank holds 500 pounds or more, then no he isn't right.

Answer 6

It will make your car lighter thus increasing fuel economy but you will not be able to calculate mileage because you have to fill up your vehicle unless you have a display that give you a mpg reading.

Answer 7

No, he's wrong. The fumes emmitted from a full tank of gas are stronger than fumes of a 1/4 tank. If I keep my tank around 1/4 full (when I'm poor) I get low 30's mpg. Full tank I am able to get high 30's mpg.

Answer 8

i odnt think it will drag u down that much to actually make a difference i ALWAYS fill my tank up i dont wanna be bothered with going to the gas station more than i have to

Answer 9

don't go below 1/2 - you can get problems that way.  personally i'm for leaving it full if possible in case you have to get the h**l out of dodge in a hurry.

Answer 10

he is very wrong.

Answer 11

ok downclover is dumb..there is no such thing as a flux capacitor running at 1.21 jigawatts

Answer 12

Yes, he's technically right, but gas is so light compared to the weight of the car that it's not going to make any significant difference.  In fact, it will actually cost more because it wastes gas each time you stop and start your engine, so if you fill up more often you'll waste more gas that way.

Answer 13

i dont believe its that big of a difference...i do know that running your vehicle under at least 1/2 a tank can cause trash to be picked up in your fuel pump which is definitely not good

--goodluck

Answer 14

Your gas mileage goes down 1-2% for every hundred pounds. Gasoline weighs somewhere around 6 pounds a gallon (versus 8 for water).

If you have a 15 gallon tank you're adding somewhere around 90 lbs. So while you can say yes, filling a tank up uses more gas, I don't think it's significant enough to not fill your tank up.  Especially if it's true that the more air space in your gas tank  the faster the gas will evaporate. I'm not sure about the validity of that one though.

Answer 15

actually, if your flux capacitor is running at 1.21 jigawats you will get the best results...they are onsale at advanced auto this week and they install free if you need a new one