I drive a ten-year-old sedan that gets decent mileage. Not great, not terrible. Last year I started tracking how much I was spending on gas and the number was higher than I thought — about a hundred sixty a month. Not life-changing money, but enough that I started looking for cuts.

Driving less was not an option. My commute is what it is. So I focused on making every gallon go further. Here is what actually moved the needle.

The Things That Actually Save Gas

1. Tire pressure. Underinflated tires increase rolling resistance. For every 1 PSI drop across all four tires, fuel economy drops about 0.2 percent. That sounds tiny but it adds up. Check your pressure monthly — the sticker inside the driver’s door tells you the right PSI, not the number on the tire sidewall. I found my tires were 5 PSI low. Fixing that saved about two dollars a tank.
2. Gas rewards programs. Most grocery chains have them. I linked my Kroger card to Fuel Points and now save twenty to thirty cents per gallon on fill-ups, sometimes more when I have been shopping a lot. The Shell Fuel Rewards program gives five cents off just for signing up, no purchase required.
3. Use the right gas. Unless your car requires premium, you are wasting money. Check your owner’s manual. If it says “regular,” use regular. Higher octane does nothing for an engine designed for 87.

Driving Habits That Matter More Than You Think

• Stop accelerating into red lights. Coasting to a stop instead of accelerating until the last second and then braking saves fuel and your brake pads. I catch myself doing the accelerate-then-brake thing all the time and have to consciously stop.
• Use cruise control on the highway. The constant micro-adjustments your foot makes use more fuel than a computer holding a steady throttle. On my last road trip, cruise control added about 3 MPG.
• Remove the cargo box when you are not using it. A roof cargo box can reduce fuel economy by up to 25 percent at highway speeds. I see cars with empty cargo boxes driving around all year. That is just burning money.

Between tire pressure, rewards programs, and better driving habits, I cut my monthly gas spending by about twenty-five dollars. Not huge, but it is three hundred a year for basically zero effort.