Is It Better to Keep Your Gas Tank Full or Empty?
By Heidi Renee Mason, June 26th, 2015 | 7 Comments »
It seems with overwhelming certainty that the agreed upon method is to keep your gas tank more full than empty. Many believe that keeping a gas tank almost empty is best as there will be less weight in the car and therefore you will get better gas mileage. While this may be true in the short-run, in the long run, most experts say keeping your tank full will save you money.
Keeping your tank full is most beneficial to your car over the long run. Your gas tank is an empty space, and whatever space is not filled by gas is filled with air. Air contains water vapors. The water vapors can condense on the sides of your fuel tank. This condensation can cause two problems. First, it can cause rust to develop on the sides of fuel tanks which are made of metal, which can cause problems in the future. The water vapors can also mix with the gas in the fuel tank, causing it to work less efficiently. This can be a problem for both plastic and metal fuel tanks.
According to Consumer Reports, gasoline acts like a coolant for your vehicle’s fuel pump motor. If your gas tank is very low, the fuel pump can suck in air. The fuel pump can then become overheated, which may lead to premature wear on the fuel pump, and eventual failure. If your fuel tank has dirt in it, it can become clogged as well. Consumer Reports goes on to advise never running your car below a 1/4 tank full.
It seems it is especially dangerous to run on a low fuel tank during the winter months. Cold temperatures can cause water to form on the gas tank’s empty walls. This water will go all the way to the bottom of the tank (since water is heavier than gas) and make its way into the fuel lines, where it can freeze. This will wreak havoc on your travel plans, not to mention it may cause further costly damage to your car.
So while having less gas in your tank may make your vehicle lighter, it has the potential to cause a number of serious problems. It appears that the safest and most cost-effective method is to run your car on no less than 1/4 tank of gas at all times. This can help you avoid potential damage to your vehicle, as well as help you avoid the obvious problem of running out of gas on the side of the road.
(Photo courtesy of Sean MacEntee)
I’ve always let my gas tank run to almost empty before filling up my car. Why pay for gas before you need to? I’ve never had a problem. This article doesn’t make sense.
Yes it does make a difference. When you let you allow your gas tank run until its almost empty is asking for problems. You are sucking up the bad part of your gasoline, thus needing fuel injection cleaning more often. I only let mine go down to the 3/4 mark.
What utter nonsense. The fuel system always draws from the bottom of the tank. If it were designed otherwise the automobile would run out of gas at the point where the system draws the gas from. Just where do you think the system draws the gas from, half way up?
Also, automobiles are equipped with fuel filters, which should be changed at regular intervals.
I learned my lesson about letting my tank get too low after my area got slammed with this storm and there were widespread power outages that lasted for day (which meant gas pumps didn’t work).
https://en.wikipedia.org/wiki/Hanukkah_Eve_windstorm_of_2006
This is really good to know. I have had to replace my fuel pump and I wonder if it is because I liked to go as far as I could before putting gas in my car. It honestly wouldn’t surprise me. However, how will I get water out of my gas tank if it is in there? Will it evaporate, or do I need to worry about it rusting my lines and fuel tank?
Best to keep tank full. Turn a full bottle of water upside and see how long it takes to empty. What you will notice is at first will come out slower but soon as you reach the halfway point it will start to pour out faster, this is due to the empty side filling up with air which pushes the water out faster! Now imagine your tank.. it will take longer to get from full to halfway then halfway to empty.
Great reply. Very simple and logical