Fuel Cost Calculator

Divide miles by MPG to get gallons, then multiply by price/gallon. Example: 1,000-mile trip in a 30-MPG car at $3.20/gal = (1,000/30) × $3.20 = $107. Add 10–15% buffer for higher highway speed (cuts MPG), AC use, and detours.

At 15,000 miles annually and $3.20/gal: 25 MPG burns 600 gallons = $1,920; 35 MPG burns 429 gallons = $1,372. Annual savings: $548. Over 10 years: $5,480, plus you're likely shielded from gas price spikes. The Toyota Prius (50+ MPG) saves over $1,000/year vs. a 25-MPG SUV.

Only if your owner's manual requires it. AAA studies show "premium recommended" cars (where it's suggested but not required) gain almost nothing from premium — sometimes 1–2 MPG, never enough to justify the 60–80¢/gal price gap. If your manual says "regular," using premium is a $300–$500/year mistake.

EPA testing uses standardized cycles that don't match real-world driving. Most drivers see 8–15% below EPA combined. The biggest factors lowering MPG: short trips (engine never warms), highway speeds above 70 mph, aggressive acceleration, AC use in hot weather, low tire pressure, and rooftop cargo (cuts MPG by 10–20%).

(1) Drive 55–65 mph instead of 75 — saves 10–20% on highway; (2) keep tires inflated to door-jamb spec — saves 3%; (3) remove rooftop cargo when not in use — saves 10–20%; (4) avoid jackrabbit starts and sudden braking — saves 15–30% in city; (5) combine errands into one trip — short cold-engine trips are 15–30% worse than warm.

At $0.18/kWh and 0.3 kWh/mile: 1,000 miles costs about $54 in electricity. Same 1,000 miles in 30-MPG gas at $3.20: $107. EV is roughly 50% cheaper per mile to fuel. The gap widens with high gas prices and shrinks with public DC fast charging (30–60¢/kWh).

For 2025, 70 cents per mile for business use, covering fuel + maintenance + depreciation + insurance. For 2024, it was 67 cents/mile. Self-employed and contractors deduct this on Schedule C. Employee mileage reimbursements at this rate are not taxable to the employee.

Diesel typically costs $0.30–$0.80 more per gallon than regular gas in the US, despite being cheaper to refine. Reasons: (1) federal excise tax is 24.4¢/gal vs. 18.4¢/gal for gas; (2) US diesel demand is dominated by trucking, which is less price-sensitive; (3) ULSD low-sulfur requirements add refining cost. Diesel cars typically get 25–35% better MPG, so per-mile cost can still favor diesel.