Is it better to fill up a gas tank when it reaches half or almost empty?

Answer 1

Another thing to know is that most modern vehicles have the fuel pump in the gas tank and the gas is what keeps the fuel pump cooled. When you let the tank go to almost empty the fuel pump is not kept cool and this will cause it to fail prematurely. Always, always fill the tank at 1/4. And get your gas from a name brand station. Never get the cheap stuff from an off brand station unless you will run out before you can get to another station and only get enough to get you a good quality station.

AnswerYa 1/4 is safe. Let it go too empty and you might suck more of the dirt in the bottom of the tank through the lines , filter - could clog up the injectors in the fuel filter is too dirty. in the winter - better to have lots of gas, condensation from being hot and then cold - due to weather can actually dilute gas. ( this is probably only a consideration if your car is hard to start in the extreme cold AnswerThe last answer is correct, with an electric in-tank pump never let it go below 1/4 tank. AnswerIt used to be advised not to let the fuel get too low in the tank. This was because dirt could lay in the bottom of the fuel tank, this dirt could then be picked up and block fuel lines and jets. Fuel these days is so well filtered that this is no longer a problem so it makes no difference when you decide to add more fuel. AnswerIt depends on what you are trying to accomplish: 1- In the winter it is better to fill the tank ASAP to prevent moisture from potentially freezing the gas line and from running out of gas due to unexpected traffic or weather related issues.

2- If you are trying to save on the extra weight of gas then fill close to empty.

3- If you are mixing lo and hi octane gas then do it at 1/2 tank.

4- In the summer doing it 1/2 is better because the gas expands, but you could also get vapor lock. So do not fill it all the way if you want it not to over expand and spill or give extra pressure in the tank.

Answerto add to the last answer another thing is that weither its a urben myth or not it is said that when your gas tank is above half you will get better mpg AnswerAnother thing to consider is that the fuel in the tank acts as the coolant for the fuel pump motor (if it's an in-tank pump). Leaving the tank mostly empty all the time can cause premature pump failure. Answer

Last answer is correct. Liquid fuel is the coolant for the pump. Driving with low fuel and taking a long curve (like on an expressway) will cause the fuel to slosh to one side and may cause pump overheating.

While every pound of weight you add to a vehicle does increase the load and therefore decrease the fuel efficiency, most vehicles are designed to operate at close to a full fuel tank. A lot of the design aspects especially the braking and suspension systems depend on calculations that include the fuel weight or what is called 'curb weight' - the weight of a vehicle with no cargo, a spare tire, and a full fuel tank.

Modern vehicles have evaporate emissions systems (EVAP) that make 'vapor lock' impossible when functioning correctly.