Fuel Economy Maintenance Checklist: Tires, Oil, Sensors, and Simple Checks
- FuelEconomy.gov notes underinflated tires can lower gas mileage by about 0.3% per 1 psi drop in average tire pressure.
- FuelEconomy.gov states using the manufacturer's recommended motor oil grade can improve gas mileage by 1–2%.
- Fixing a vehicle that is noticeably out of tune or has failed an emissions test can improve gas mileage by as much as 40%, according to FuelEconomy.gov.
What We Know (Sourced)
FuelEconomy.gov provides a consumer-focused maintenance guide titled "Keeping Your Vehicle in Shape". It lists common maintenance factors that affect fuel economy, including tire pressure, motor oil selection, air filters, and check engine diagnostics.
FuelEconomy.gov includes specific numeric guidance, such as:
- Underinflated tires can lower gas mileage by about 0.3% per 1 psi drop in average tire pressure.
- Using the manufacturer's recommended motor oil grade can improve gas mileage by 1–2%.
- Fixing a vehicle that is noticeably out of tune or has failed an emissions test can improve gas mileage by as much as 40%.
DOE also provides general consumer guidance on fuel economy fundamentals and behavior-based fuel savings, which helps put maintenance in context: maintenance is one category of levers, not the only one.
The Checklist (Practical)
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1) Tire pressure to placard PSI
Check monthly and during cold snaps. Related: cold weather tire pressure and tire pressure and MPG.
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2) Address a check engine light
FuelEconomy.gov notes poor maintenance can reduce MPG and that "out of tune" conditions can materially change mileage. Related: check engine light and fuel economy.
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3) Use the manufacturer's recommended motor oil grade
FuelEconomy.gov states this can improve MPG by 1–2% in many cases. Related: motor oil and MPG.
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4) Treat air filter claims cautiously
FuelEconomy.gov explains that older vehicles may see fuel economy improvement from replacing a clogged air filter, while modern vehicles are less likely to. Related: air filter and MPG.
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5) Reduce compounding losses
If you stack underinflated tires + heavy roof drag + aggressive driving, your results may degrade more than any single lever suggests. Related: roof racks and MPG and aggressive driving.
How to Measure MPG Before and After
If your goal is to confirm savings (not just "feel" a difference), measure the impact:
- Use tank-to-tank MPG (or consistent EV kWh/100 miles logs).
- Measure for multiple fill-ups before and after the change.
- Keep your route and driving style as consistent as possible.
For fuel-cost framing, compute cost per mile for your baseline and improved MPG values. Related: cost per mile.
Want a quick estimate?
Translate MPG changes into dollars per mile and annual cost.
Try the Cost Per Mile CalculatorWhat's Next
- Pick one lever (for example, tire pressure) and fix it first.
- Measure for a month, then move to the next lever (oil grade, diagnostics, etc.).
- Use weather-aware expectations: winter and summer can change MPG materially. Related: cold weather and hot weather.
Frequently Asked Questions
Will maintenance always improve MPG?
Not always. Maintenance often prevents avoidable losses (for example, low tire pressure), but if the vehicle is already well maintained, the change may be small. FuelEconomy.gov provides the best baseline expectations for common items.
What's the fastest checklist item to verify?
Tire pressure is usually fastest: you can check and correct it in minutes. FuelEconomy.gov provides a baseline estimate for the MPG impact of underinflation.
Should I focus on maintenance or driving behavior first?
Both matter. Maintenance prevents avoidable losses, while behavior can change energy use immediately. If you're not sure, start with a tire-pressure check and a two-week MPG log, then test one driving change (like smoother acceleration).