Gas Tops $4.25 a Gallon: The Maintenance Fixes That Actually Save Fuel

Where prices stand

AAA put the national average for regular at $4.28 a gallon on September 10, 2026 – up 13 cents in a week, from $4.01 a month earlier and $3.19 a year earlier. AAA tied the jump to crude oil climbing back toward $100 a barrel amid volatility in the Strait of Hormuz.

California ($5.89), Washington ($5.53) and Hawaii ($5.40) were the most expensive states; Indiana ($3.56), Mississippi ($3.80) and Texas ($3.83) the cheapest. For electric cars, AAA put the average public charging price at 42 cents per kilowatt-hour.

What actually saves fuel

The U.S. Department of Energy's fueleconomy.gov tested the usual advice. The results are smaller than most tips promise, but they are real:

1. Keep the tires at the right pressure. Worth 0.6% better mileage on average and up to 3% in some cases. The right number is on the sticker inside the driver's door, not on the tire. Check once a month, when the tires are cold.
2. Use the oil grade your manual lists. The wrong grade costs 1% to 2%. If the manual says 0W-20, do not let anyone put 10W-30 in because it is "thicker."
3. Fix what the check engine light is telling you. A faulty sensor can make the engine run rich and burn more fuel. The Department of Energy does not put a single number on it, because it depends on the fault – but a code read is cheap and tells you whether it matters.

The upsell to skip

A new engine air filter is often sold as a mileage fix. On modern fuel-injected engines, fueleconomy.gov found that a clogged air filter does not hurt fuel economy – it only slows acceleration. Replace it on the schedule in your manual, not to save gas.

What a mobile mechanic can do in the driveway

Oil changes, check-engine diagnostics and tire-pressure sensor problems are all standard mobile jobs, done where the car is parked. Mobile oil change · Mobile diagnostics · What it costs