Why Is My Gas Mileage Getting Worse?

Short answer

MPG often falls because of cold weather, short trips, under-inflated tires, extra weight, or a partial-fill measurement error — not always mechanical failure.

Measurement mistakes

MPG needs full-tank cycles. Partial fills skew gallons. Compare three tanks before panicking.

Driving pattern

Stop-and-go commutes, idling, and winter warm-ups burn fuel without adding highway miles.

Maintenance

Air filter, spark plugs, alignment, and tire pressure affect economy. Fix the cheap items first.

Track the trend

Gas Tracker AI shows MPG over time so you see a real trend, not one bad tank.