The EV Route

Efficiency

How much range you lose by driving faster

Of everything that affects how far an electric car goes, speed is the largest thing under your direct control on the day — larger than temperature, and far larger than anything you can do about tyres or load.

Updated 3 min read 14 citations

Mountain road curving across a bare alpine slope with peaks behind
Iamthestig · CC BY-SA 3.0 · Wikimedia Commons
Consumption against motorway speed Energy use per hundred kilometres rises from about thirteen and a half kilowatt hours at seventy kilometres per hour to around thirty-one at a hundred and forty, with the curve steepening as speed increases. 091726340285684112140Steady speed (km/h)kWh per 100 kmConsumptionSweet spot
The single biggest lever you control. Aerodynamic drag rises with the square of speed and the power needed to overcome it with the cube. Dropping from 130 to 110 km/h cuts consumption by roughly a quarter — which on a long route often removes an entire charging stop, saving more time than the slower speed costs. Representative of a mainstream saloon; absolute values differ by vehicle, the shape does not.

The physics, briefly

Two forces resist a car at constant speed: rolling resistance, which is roughly proportional to speed, and aerodynamic drag, which is proportional to the square of it. Because power is force times velocity, the power needed to push through the air rises with the cube of speed. At motorway speeds drag dominates completely, which is why the curve above steepens rather than staying straight.

This is true of combustion cars too. It is more visible in an electric car for two reasons: there is no idling or gearing to muddy the picture, and the instantaneous consumption readout makes it legible in a way a fuel gauge never did.

The journey arithmetic

The trade is between time lost to slower driving and time lost to an extra charging stop. Over 500 km, dropping from 130 to 110 km/h costs roughly forty minutes of driving. If it removes one twenty-five-minute stop, it costs fifteen minutes net — but it also removes the risk associated with that stop being occupied, broken, or in the wrong place. On routes where charging is sparse, that risk reduction is worth more than the fifteen minutes.

The calculation flips on short journeys. Under about 250 km, where no stop is needed either way, driving slower buys nothing but a later arrival.

What else moves the number

  • A roof box costs more than almost anything else. Frontal area and disturbed flow together can add 20-30% at motorway speed. A rear-mounted carrier is usually much cheaper aerodynamically.
  • Cold is the second-largest factor. Cabin heating draws real power and a cold pack is less efficient before it warms.
  • Tyre pressure matters more than tyre choice for most people, and it is free to correct.
  • Load matters less than expected on the flat and considerably more in hills, where you are lifting it.
  • Headwind is indistinguishable from speed as far as the car is concerned — a 25 km/h headwind at 110 km/h is aerodynamically 135 km/h.
How much range do I lose at 130 km/h?
Roughly a quarter compared with 110 km/h, for a typical saloon. The exact figure depends on the car's drag coefficient and frontal area, but the direction and rough magnitude are consistent.
Is it worth driving slower to avoid a charging stop?
On journeys long enough to need a stop, usually yes — and more so where chargers are sparse. On journeys short enough not to need one, no.
Does a roof box really matter that much?
Yes. It is one of the few modifications that can cost more range than a 20 km/h speed increase. Remove it when it is not in use.
What speed is most efficient?
For pure consumption, quite slow — around 60-70 km/h for most cars. For journey time, the practical optimum on a long motorway drive is usually 105-115 km/h.
Alpine toll road winding between rocky slopes under a broad sky
Arne Müseler · CC BY-SA 3.0 de · Wikimedia Commons

References

Every citation below links to the original peer-reviewed record on PubMed or via DOI. Nothing here is a substitute for medical advice.

  1. Effect of Ambient Temperature on Electric Vehicles’ Energy Consumption and Range: Model Definition and Sensitivity Analysis Based on Nissan Leaf Data Iora P, Tribioli L · World Electric Vehicle Journal · 2019 · Journal article DOI
  2. Electric Vehicle Energy Consumption Modelling and Prediction Based on Road Information Wang J, Besselink I, Nijmeijer H · World Electric Vehicle Journal · 2015 · Journal article DOI
  3. Real‑World Energy Consumption Comparison Between a Diesel Vehicle and a Battery‑Electric Vehicle Fike M, Predin A, Roger A · Renewable Energies, Environment and Power Quality Journal · 2026 · Journal article DOI
  4. Dynamic Electric Vehicle Route Planning via Traffic Flow Prediction and Charging Service Integration Zhang Y, Shen X, Wang Y · Processes · 2026 · Journal article DOI
  5. Resilience-Oriented Predictive Energy Management and Route Adaptation for Long-Distance Electric Vehicles Under Charging Infrastructure and Road Network Uncertainties Khan B, Ullah Z, Gruosso G, et al. · World Electric Vehicle Journal · 2026 · Journal article DOI
  6. Machine Learning-Based Prediction of Electric Vehicle Energy Consumption Using Real-World Field Data R.Vishnuvardhan, T BanuChandar · Research Digest on Engineering Management and Social Innovations · 2026 · Journal article DOI
  7. Research on Energy Management Strategy for Range-Extended Electric Vehicles Based on Eco-Driving Speed Liu H, Yang K, Sun W, et al. · Applied Sciences · 2025 · Journal article DOI
  8. Planning for Medium- and Heavy-Duty Electric Vehicle Charging Infrastructure in Distribution Networks to Support Long-Range Electric Trucks Then J, Agalgaonkar A, Muttaqi K · Energies · 2025 · Journal article DOI
  9. Co-Optimization of Charging Strategies and Route Planning for Variable-Ambient-Temperature Long-Haul Electric Vehicles Based on an Electrochemical–Vehicle Dynamics Model Zhang L, Zhang M, Shan H, et al. · Sustainability · 2025 · Journal article DOI
  10. Optimisation of Electric Vehicle Charging Stations Planning Based on Macro and Micro Perspectives WANG Q, DENG K, YAN J, et al. · Promet - Traffic&Transportation · 2025 · Journal article DOI
  11. Personalised electric vehicle charging stop planning through online estimators Shafipour E, Stein S, Ahipasaoglu S · Autonomous Agents and Multi-Agent Systems · 2024 · Journal article DOI
  12. Electric Vehicle Distribution Route Optimisation and Charging Strategy Considering Dynamic Loads Wu Q, Tian M · Polish Journal of Environmental Studies · 2024 · Journal article DOI
  13. Multi-Objective Electric Vehicle Route and Charging Planning with Contraction Hierarchies Cuchý M, Vokřínek J, Jakob M · Proceedings of the International Conference on Automated Planning and Scheduling · 2024 · Journal article DOI
  14. Electric Vehicle Health Monitoring with Electric Vehicle Range Prediction and Route Planning Jayaram J, Chetan J, Nayak B · Journal of Informatics and Web Engineering · 2024 · Journal article DOI