Your vehicle will use more fuel whenever the engine has to work harder than normal, especially at high speeds, during harsh acceleration and braking, with extra weight, in stop‑start traffic, and when the car is poorly maintained. Understanding these situations helps you cut running costs and reduce wear on your car.

Quick Scoop

  • High speed, rapid acceleration, heavy loads, and under‑inflated tyres all make your engine work harder and burn more fuel.
  • Short, cold trips, city traffic, and lots of idling are surprisingly wasteful compared with smooth, steady cruising.
  • Poor maintenance (wrong oil, worn parts, clogged filters) can quietly increase fuel usage over time.

When your vehicle uses more fuel

1. Speed and driving style

  • Driving fast on motorways dramatically increases aerodynamic drag, so consumption rises sharply once you go much above roughly 50–60 mph / 80–100 km/h. One guide notes around 30% more fuel at 70 mph than at 50 mph over the same distance.
  • Aggressive acceleration and hard braking waste the energy you just paid for at the pump, so smooth, progressive inputs are far more efficient.

2. Traffic, routes and trip length

  • Stop‑start city driving, with frequent gear changes and pulling away from lights, is one of the least efficient scenarios for fuel use. Idling in queues burns fuel while you go nowhere.
  • Very short trips are costly because a cold engine runs rich (more fuel per unit of air) and never reaches its optimal temperature. This is why the same car can feel “thirsty” on lots of short errands but reasonable on a longer run.

3. Weight, drag and load

  • Carrying extra passengers, luggage, roof boxes, bike racks or towing a trailer all add weight or drag, forcing the engine to work harder for the same speed. The effect is especially noticeable on hills and during acceleration.
  • External accessories like roof boxes and roof‑mounted racks increase aerodynamic drag even when empty, so they can noticeably raise fuel use at motorway speeds. Removing them when not needed helps keep consumption down.

4. Tyres, gears and mechanical condition

  • Under‑inflated or worn tyres increase rolling resistance, acting like you are driving with the handbrake slightly on, so more fuel is needed to maintain speed. Keeping pressures at the recommended level improves both economy and safety.
  • Driving in the wrong gear (too low a gear for the speed, revving unnecessarily high) wastes fuel by keeping the engine away from its most efficient operating range. Modern cars often indicate when to shift up to help reduce consumption.
  • Using engine oil that is too thick, or driving with a worn clutch, blocked exhaust, or other faults, all increase internal resistance and slippage so the engine burns more fuel to deliver the same performance.

5. Climate, seasons and accessories

  • Cold weather increases fuel use because engines take longer to warm up and other components (fluids, tyres) are less efficient, so winter driving usually returns poorer mileage than summer.
  • Running energy‑hungry electrical accessories such as air conditioning, rear window heaters and demisters puts extra load on the engine via the alternator, which slightly increases fuel consumption, especially at low speeds.

Simple ways to reduce fuel use

  • Drive at moderate, steady speeds and avoid harsh acceleration or late, heavy braking.
  • Plan routes that minimise stop‑start traffic and combine short trips so the engine warms up once instead of many times.
  • Keep tyres correctly inflated, remove unnecessary weight and roof‑top accessories, and follow the recommended service schedule.

Information gathered from public forums or data available on the internet and portrayed here.