I understand that driving less weight around gives you better gas mileage. People suggest I take the junk out of my trunk. So, do I get better gas mileage when my gas tank is almost empty than when it is full? Can I get better mileage by not filling up the tank?
Yes, you will get slightly better gas mileage, but you will end up behind because of the frequent trips to the gas station because you are always almost on empty.
Anytime you remove weight from a vehicle it helps to improve fuel mileage or performance. This includes the weight of the fuel in the vehicle.
Tester
In theory, yes, but it’s hard to tell what your gas mileage is if you don’t top off the tank each time. Also, more frequent trips to the gas station may cancel out your savings.
In the grand scheme of things, always driving with a nearly empty tank is “straining out a gnat”. Speeding and accelerating towards each and every red light is “swallowing a camel”.
You’ll get bigger gains from making sure the tires are energy efficient and filled up to the proper PSI, more relaxed driving and an engine in good tune, than from taking 50 pounds out of your trunk.
Oh yeah, you may also me shortening the life of your fuel pump. The gas in the tank lubricates and cools the pump.
Hardly worth the effort.