How does filling your gas tank half way every time help?

There is no savings at all.

Most people fill the tank all the way up when it gets down to half a tank. That way they always have gas should they need to go somewhere in an emergency.

If you have sediment in your gas tank the lower you let your tank go the greater the chance it will get sucked into the gas filter then you’ll have costly repairs

.always fill the tank when possible to get the best gas mileage and peak performance from your unit.

In addition to the first two posters there is another advantage to keeping the tank full in that condensation cannot accumulate with a full tank. Keeping water from condensing on the walls of the tank increases the performance of your vehicle. This is mostly notable in vehicles with larger tanks (like diesel semi-trucks) but happens in any vehicle. Warm afternoon and cold night with low fuel tank equals condensation in tank. This is not a hypothetical thing, it is a fact.

the theory is that because gas weighs about 6 pounds per gallon, not having 7-10 gallons will save 40-60 lbs of weight, and therefor, result in better fuel economy. i’ve tried it. i didn’t see a noticeable improvement. and i got tired of having to stop for gas 3-4 times per week

here is what i have always done, when the gas gauge gets to half a tank, i always fill it up, its cheaper this way because it will add some weight to the rear in winter driving, great for emergencies, easy on the the gas tank and fuel pump. make sure you put in some fuel injector cleaner every 3000 miles, and put some heat in as well. That will get rid of the water that may be in your gas.

it wouldnt save you anything. when my truck gets down to half a tank i fill it back up.