Simple ways to improve fuel economy in London

Why London driving is hard on your fuel bill

London is a wonderful place to drive short distances and a punishing place to drive efficiently. Average speeds in the central zone often sit below 10mph, and even on a decent run you will meet a 20mph limit, a set of lights, a bus pulling out and a pedestrian crossing before you have covered half a mile. Every one of those stops asks the engine to burn fuel to get you moving again, and every heavy-footed start burns more than a gentle one.

The encouraging part is that fuel economy is less about the car and more about the person behind the wheel. A handful of consistent habits can trim your weekly spend noticeably without changing what you drive, where you park or which route you take to work.

Drive smoothly and read the road further ahead

Harsh acceleration is the single biggest waste in city driving. Aim to get up to speed briskly but progressively, then settle. In a 20mph zone there is rarely any benefit to racing between junctions, and the fuel you burn reaching 30mph before braking back to 20 is simply lost as heat from your brake discs.

Look two or three cars ahead rather than at the bumper in front. If you can see a red light, a queue forming or a bus indicating at a stop, lift off the accelerator early and let the car roll. Modern engines cut fuel almost entirely when you are off the throttle and in gear, so coasting down to a junction uses far less than braking hard from 25mph at the last moment.

• Anticipate lights. Ease off rather than sprinting to a red, and time your arrival so you are still moving when it turns green.
• Use the gearbox. In a manual, change up early — third gear is perfectly happy through most residential streets.
• Keep a steady throttle. Constant small adjustments cost more than holding a consistent position.
• Skip the race away from roundabouts. Brisk, not aggressive, is the sweet spot.

Check your tyres and keep the basics right

Under-inflated tyres are a quiet thief. They increase rolling resistance, wear the shoulders of the tyre and make the car feel vague in the wet. A tyre sitting 10% below its recommended pressure can cost you a couple of percent in fuel, and in London's stop-start traffic that adds up over a month.

Check pressures every fortnight, when the tyres are cold, using the figures in your handbook or on the driver's door pillar rather than the maximum printed on the sidewall. Remember that London's weather swings: pressures drop in a cold snap and rise on a long motorway run.

The rest of the basics matter too. A clogged air filter, tired spark plugs, old engine oil or a sticking brake caliper all drag on economy. Keeping to your service schedule is not glamorous, but a well-maintained engine in a car that does mostly short urban trips needs attention more often, not less, because it rarely gets properly warm.

Stop idling — it is pure waste

Idling returns exactly zero miles per gallon. If you are stationary for more than about 30 seconds and not in traffic, switch the engine off. Outside the school gates, waiting for a passenger, queuing at a car wash or sitting in a layby while you check your phone are all moments where the engine is doing nothing but burning fuel and adding to the air your neighbours breathe.

Some London boroughs do enforce against unnecessary idling, so it is worth treating this as more than good manners. If your car has a stop-start system, let it work as intended rather than disabling it out of habit — the starter motor and battery are built for it. And do not idle to "warm the car up" on a frosty morning. Thirty seconds is plenty before you drive gently; the engine warms faster under light load than sitting still.

Lighten the load and think about the air conditioning

Every extra kilogram costs fuel, and Londoners are experts at carrying things around "just in case". Clear the boot of the golf clubs, the crate of paperwork and the winter grit you never used. Remove roof bars and roof boxes when they are not needed — a bare roof rack at 20mph is a small penalty, but at 50mph on the North Circular it is a significant one.

Air conditioning is a genuine trade-off. At low speeds, open a window; at higher speeds, closed windows and air conditioning are usually more efficient than the drag of an open window. On mild days, use the ventilation setting without the compressor and you will barely notice the difference.

Plan the journey so you stop less

The most fuel-efficient route is rarely the shortest one. A slightly longer run with fewer junctions, fewer right turns across traffic and fewer sets of lights will usually beat a direct crawl through a bottleneck. Check live traffic before you leave, and consider shifting your departure by 20 minutes to miss the worst of the school run.

For regular trips, ask whether the car is the right tool that day. A walk to the local shop, a bus for the cross-town journey or parking once and walking between appointments all cut fuel to zero for part of the trip. Combine errands into one loop while the engine is warm rather than making three cold starts, and your weekly fuel bill will quietly fall — no new car required.