MPG from miles driven and gallons used.
MPG = miles driven ÷ gallons used. Fill up, drive, fill up again to measure.
Track over several tanks for a reliable average — one tank can be skewed by conditions.
A single tank can be thrown off by short trips, cold weather, or heavy traffic, all of which lower real-world MPG temporarily — averaging several fill-ups smooths out these one-off effects into a more representative number.
300 miles on 10 gallons = 30.00 MPG.
EPA numbers assume steady speed and moderate conditions. Real-world driving (traffic, weather, cargo) can drop MPG 10–20%.
Most cars are most efficient at 45–65 mph. Above 65, aerodynamic drag rises steeply.
Yes — underinflated tires increase rolling resistance and can measurably reduce fuel economy, which is why checking tire pressure is a standard fuel-saving tip.