Swift | Silent | Deadly

Micropreparedness: Keep Your Gas Tank Half Full

By , on

This isn’t exactly news to the preppers out there, but an excellent way to improve your preparedness is to keep your car’s gas tank half full..at least. Keeping some gas in your tank serves more purposes than you might think. Let’s talk about them.

This article contains affiliate links.

Why Keep Your Gas Tank Half Full?

Keeping one’s gas tank half full is something baked into the culture of emergency services. At my job as a paramedic, we always fill the tank before it falls below half full. It has to be at at least 3/4s before we turn it over to the next crew in the morning. It always shocks me when I see a friend, family, or co-worker with a nearly-empty tank.

There are a lot of good reasons to keep your gas tank half full. Let’s talk about them.

Reduced Pressure During Shortage

First, it ensures you have some fuel. Here in the Southeast we’ve had some fuel shortages in recent memory. Beginning the last fuel situation with a nearly-full tank took a lot of pressure off of us. We cut way back on non-necessary driving and went only to school and work. Everything else – grocery store trips, etc. – were planned around those trips.

This is normally where I start thinking about filling up.

This was helpful in another way, too. It allowed me to choose my time and place to get fuel. Rather than wait in long lines, I had the ability to wait until a better time to stop and gas up. I could also plan my route to work to let me drive by the maximum number of gas stations, because more stations means a better chance one might have fuel. I wouldn’t have been able to do this had I gone into the shortage “running on fumes.”

One more thing: during shortages fuel prices go up. Sometimes WAY up. I’d prefer to have to buy as little fuel as possible under max pricing.

Gas to Bug Out

Fuel in the tank also means gas to get out of Dodge. If you have to bug out, you’ll want to start with at least half a tank. I know that none of us imagines ourselves leaving our warm, dry, comfortable homes in an emergency. It could happen, though. Wildfire, industrial accidents…any number of things could force a prudent evacuation from your home.

You want max potential miles in your tank when an emergency starts.

If you do have to bug out a lot of other people probably will, too. This will probably mean slow going and sitting in traffic, which will burn fuel. It will also mean long lines at gas stations. Begin the emergency with at least some gas in the tank so you get on the road ASAP.

Longevity of Your Car

Keeping gas in the tank is also good for your car. As the fuel level in your car goes down, air moves in to fill the space. Air contains moisture. During hot and cold fluctuations that occur daily with the sun rising and setting, this air warms up causing condensation to occur inside the tank. This adds a small amount of water to your fuel, making it less efficient. On older cars with metal gas tanks this can even cause rust to form.

There also may be some particulate matter at the bottom of your gas tank. Even with newer, plastic tanks that don’t rust sediment can still accrue over time. If you let your car run very low on fuel this stuff can get sucked into your fuel lines. Here it may clog your fuel filter, and some of it will make it into the engine. For the sake of longer life and better efficiency of your car, keep your gas tank half full, at least.

I generally try to fill up well before the gauge hits half, usually around 3/4s of a tank. When I get to the three-quarter’s mark I start planning my next fill-up. This can require a lot of stops for fuel if you have a very long commute or do a lot of distance. In my opinion it’s worth it.

Where and When to Get Gas

I’ve read several books on auto maintenance and driving lately. All of them recommend two tips to getting the most mileage out of dollars spent at the gas pump: where and when to get gas.

Where to get gas: Gas is best – as measured by the power it can produce – when fresh. Make a habit of getting fuel from stations with high turnover, i.e. the ones that sell a lot of gas. I got slightly out of my way on the way to work to get gas at a very popular gas station.

When to get gas: the temperature of gas stored in underground tanks fluctuates throughout the day. In morning, when it is cooler, gas is denser and you actually get more fuel for your dollar. I have made it a habit to swing by the gas station on my way to work. It only means leaving a couple minutes early, but it means more fuel, and not having to worry about gassing up on the way home when I’m tired.

Closing Thoughts

Keeping your gas tank half full is an easy way to increase your preparedness. You have to buy fuel anyway; just make a habit of buying it a little more frequently. Keeping your gas tank half full also makes your life easier sometimes. You don’t have to get gas when you’re forced to get gas by the “E” light.  Instead, you can get gas at a time and place of your choosing. And if you’re running late, guess what? That’s right – you don’t have to stop for gas.

Keep Reading