How to Improve Your Fuel Economy (Hypermiling Basics)
Fuel economy is mostly physics. Every litre fights three things: air resistance, rolling resistance and the energy lost when you brake. Beat those and your MPG climbs. Here’s where the energy goes — and what to do about it.
Where your fuel actually goes
- Aerodynamic drag dominates at speed and rises with the square of velocity — double the speed, quadruple the drag.
- Rolling resistance (mostly tyres) matters more at low speed and with extra weight.
- Braking turns fuel you already burned into waste heat. Every avoidable brake is wasted money.
The high-payback changes
- Slow down a little. Because drag is exponential, the last 10 mph on the motorway is the thirstiest. Cruising 5–10 mph slower is the single biggest economy win.
- Keep momentum. Look far ahead, ease off early, and time your approach to lights so you roll rather than stop. Stops cost you the fuel to get moving again.
- Accelerate gently but get into top gear promptly. Lugging in a low gear and flooring it both waste fuel; brisk-but-smooth, then high gear, is the sweet spot.
- Inflate your tyres correctly. Cheap, quick, and worth a couple of percent.
- Shed weight and drag. Clear the boot; remove roof boxes and racks when unused.
Climate, cold and short trips
Cold engines are inefficient until warmed up, so several short cold-start trips burn far more than one combined run. In winter, economy drops anyway — thicker oil, denser air, more electrical load. Combine errands and avoid unnecessary idling to warm up.
Measure, don’t guess
Brim the tank, reset the trip meter, drive normally, then brim again and divide distance by fuel used — that’s your real economy, which is often well below the official figure. Convert it to a consistent unit with the MPG to L/100km converter, then see what it means in money with the fuel cost calculator. For the full money-saving checklist, read how to save money on fuel.