Eco-driving: use less fuel and cut emissions

The fundamentals of eco-driving are simple: smooth inputs, sensible speeds, a well-maintained car and smarter trip planning. Together they can noticeably reduce your fuel costs — and the emissions that go with them.

Smooth acceleration and braking

The single biggest difference between an efficient driver and a heavy-footed one is how they use the accelerator and brakes. Every time you brake hard, you throw away the kinetic energy you spent fuel building up.

• Accelerate gently. Build speed gradually rather than pressing hard and then easing off. In a manual car, shift up through the gears early — aim to be in the highest gear the engine will pull comfortably without labouring.
• Read the road ahead. Look well ahead so you can ease off and coast to a junction or red light rather than braking at the last moment. Anticipating stops is one of the most effective fuel-saving skills there is.
• Maintain a steady speed. Constant speed is far more efficient than yo-yoing between accelerating and braking. Cruise control on long, flat motorway sections helps with this.
• Leave more space. A larger gap ahead lets you anticipate slow-downs earlier and coast more, which also reduces stress.

Speed and motorway driving

Aerodynamic drag increases with the square of speed: driving at high speed takes considerably more power (and fuel) than driving a little more slowly. On longer motorway journeys, speed is the most powerful lever you have.

• Keeping to the speed limit rather than 10–15 mph/km/h above it can meaningfully cut fuel use on a long run.
• If you use cruise control, set it to the speed limit rather than above — even modest reductions matter over long distances.
• On dual carriageways and motorways, stay in the left lane (or right lane in left-hand-traffic countries) unless overtaking, which also helps traffic flow and reduces unnecessary braking.

Reduce idling

An idling engine burns fuel and produces exhaust while going nowhere. Modern engines do not need warming up with prolonged idling — they warm faster and more evenly when driven gently from the start.

• Switch off the engine if you expect to be stationary for more than a minute or two — at level crossings, school pick-ups, drive-throughs or sitting in long queues.
• Many newer cars have stop-start systems that do this automatically; let them work rather than disabling them.
• Avoid idling with the air-con running to cool the car before you set off — open the doors briefly to flush hot air first.

Lighten and de-clutter the car

Every kilogram the engine carries uses extra fuel. A car loaded with things that live in the boot "just in case" is heavier than it needs to be on every trip.

• Remove heavy items you don't need for this journey.
• Remove roof racks, roof boxes and bike racks when you're not using them. They add both weight and significant aerodynamic drag at speed — a roof box can increase fuel consumption noticeably on motorway runs.
• Keep only the tools and equipment you actually need in the boot.

Tyre pressure and car maintenance

A poorly maintained car works harder than it needs to. A few simple checks pay back in lower running costs.

• Check tyre pressure monthly. Underinflated tyres increase rolling resistance, which increases fuel use and tyre wear. The correct pressures are in the car's manual or on a sticker inside the driver's door or fuel cap. Check when the tyres are cold.
• Service the car on schedule. A fresh air filter, clean fuel system and correct engine oil all let the engine run as efficiently as it was designed to.
• Watch dashboard warning lights. A faulty oxygen sensor or engine management issue can significantly increase fuel consumption, so get them checked promptly.
• Make sure wheel alignment is correct — misaligned wheels scrub against the road and waste energy.

Plan and combine trips

Short cold-start trips are the least efficient journeys you make. A cold engine, before it reaches operating temperature, uses noticeably more fuel per kilometre than a warm one — and catalytic converters don't work properly until they're hot, so cold short trips produce disproportionately high emissions too.

• Combine errands into one trip rather than making several separate short journeys. Doing everything in one loop — school run, supermarket, post office — uses far less fuel than three separate cold starts.
• Avoid congestion where you can. Stop-start traffic in queues uses fuel without making progress. Adjusting your departure time, using a route with fewer traffic lights or working from home on peak days can all help.
• For the shortest trips — under a mile or two — consider whether walking or cycling is realistic. Short car journeys are the most fuel-inefficient per distance.

Air-con vs. windows

Both air-conditioning and open windows have a fuel cost — one from the compressor load, the other from increased aerodynamic drag. The trade-off depends on speed:

• At low speeds in town, opening windows has little aerodynamic penalty and is usually the more efficient option.
• At higher speeds (motorway/highway), the drag from open windows can outweigh the air-con load, so air-con becomes relatively less costly.
• In both cases, the most efficient option is to park in shade, use sunshades and ventilate the car before setting off, so you need less cooling overall.
• Use the air-con's economy or re-circulation setting where available, and turn it off when you've reached a comfortable temperature.

EVs: the same rules apply

Electric vehicles don't burn petrol, but they still convert stored energy into motion — and all the same principles apply to extending their real-world range.

• Smooth driving extends range. Gentle acceleration and making the most of regenerative braking (which recovers energy back into the battery) are particularly effective.
• Speed matters just as much — aerodynamic drag is physics, regardless of the energy source.
• Climate control is a significant energy use in EVs. Pre-condition the cabin while still plugged in (most EVs allow this via an app), so you're using grid power rather than battery power to heat or cool it.
• Remove roof racks and boxes when not in use — range impact at motorway speeds is real.

Your eco-driving habits checklist

1. Check your tyre pressures this week — correct them if needed.
2. Remove anything from the boot you don't need for the journey.
3. Take off the roof rack or box if it's been on since the last trip.
4. On your next drive, try accelerating and braking more gradually than usual.
5. When you see a red light ahead, ease off the accelerator and coast in gear.
6. Switch the engine off next time you're waiting more than a minute.
7. Combine your next set of errands into one trip rather than separate journeys.
8. On your next long drive, set cruise control to the speed limit and note the difference.

• Tyre pressures checked and correct.
• Roof rack / bike rack removed when not in use.
• Boot cleared of unnecessary weight.
• Car serviced on schedule.
• Errands combined into single trips where possible.
• Smooth acceleration and braking practised.
• Engine switched off when waiting.
• Air-con used sensibly — pre-vented car, re-circ on.