Running on Empty: When is the best time to fill up your tank?
When I first started driving at 16, I was fortunate to have a vehicle with two gas tanks. I could switch between the two if one tank ever got low on fuel. My 1984 GMC Sierra did not have a very accurate fuel gauge and would definitely not tell me how many miles I could go before my tank was empty. I would manually calculate my gas mileage to determine how far I could travel until I needed to refuel. On a couple of occasions, I actually did run out of gas before my estimated miles-to-empty was reached, but I had a second tank of gas that I could quickly flip to and continue on my way (to the closest gas station). Fortunately, my truck also had a mechanical fuel pump that would not break down when the vehicle was low or completely out of gas.
Much has changed on vehicles since my truck was manufactured, including the fuel pump, more accurate fuel gauges, and the miles-to-empty readings. In our shop, we frequently have vehicles coming in with less than one-quarter of a tank of gas, which can actually be quite detrimental to a vehicle’s electric fuel pump. The newer fuel pumps are cooled by gasoline in the fuel tank, and they can easily break when the pump gets too hot. This overheating issue typically happens when the fuel tank is empty. This can then cause contaminants to enter the fuel system, which can equate to very costly repairs.
Another driver experience improvement, the miles-to-empty reading, is much less accurate than drivers may realize. AAA recently conducted a study of sixteen different vehicles, and they found that every vehicle in the study underestimated the miles-to-empty readings between 6 and 55 miles (AAA Explorer, Jan/Feb/March 2022). Quite a few vehicles also overestimated and underestimated their fuel economy.
This research supports that basing your tank refills on the variable and inconsistent miles-to-empty and miles-per-gallon readings is not the best option. We recommend refueling when your gas gauge is to the one-quarter mark, allowing you enough gas in the event of an emergency or supply chain issues (which is all too common right now). This will also keep your fuel pump lubricated and cooled with gasoline at all times, helping to reduce the likelihood of the pump going bad.
If you have any concerns regarding your fuel economy, give us a call so we can answer any questions you may have, or schedule an appointment here.