In this article, we'll look into the main reasons behind the EV range fluctuations and share some tips to help you maximize your car's battery.
If you drive an electric vehicle, you might have noticed that the range doesn't always match what’s promised on the spec sheet. Don’t worry—you’re not alone! There are several factors that can affect how much energy your EV uses. In this article, we'll break down the main reasons behind this and give you some tips to help you get the most out of your car's battery.
Understanding the rated range in the product sheet
When shopping for a vehicle, you will typically find estimated consumption or range figures on the product sheet. These estimates are calculated using two main testing procedures: the Worldwide Harmonized Light Vehicle Test Procedure (WLTP) and the EPA Federal Test Procedure (commonly known as FTP-75 or simply EPA estimates). Most countries rely on the WLTP, while in the U.S., the numbers are based on EPA guidelines.
Both methods aim to give potential buyers comparable consumption and range estimates across different vehicle models. However, since these are standardized tests and manufacturers often highlight the best possible outcomes, the figures provided rarely match the actual driving experience. In real-world conditions, vehicles often perform differently than what’s stated in the product sheet.
And that takes us to…
Factors that impact the actual range of EVs
A vehicle's energy consumption is influenced by several factors, including the vehicle itself, driving style, route, and weather conditions. The vehicle's contribution to energy use primarily depends on its powertrain and aerodynamic efficiency. Every driver has a unique driving style, and with conscious effort, anyone can reduce consumption by driving more efficiently. Additionally, different routes demand varying amounts of energy due to factors like elevation changes, road surface materials, and traffic conditions.
The impact of weather on electric vehicle energy consumption can be divided into two categories: atmospheric weather and road weather conditions. Atmospheric weather refers to phenomena that occur in the air, while road weather conditions involve the state of the road surface, including dryness, water, snow, or ice.
Key atmospheric factors affecting EV energy consumption include temperature, solar radiation, wind, air pressure, humidity, and precipitation. Of these, temperature has the biggest influence on the powertrain, with humidity playing a minor role. The vehicle's cabin is primarily affected by temperature and solar radiation, as it acts much like a greenhouse, trapping heat inside.
The aerodynamic resistance of the vehicle is affected by wind speed and direction, as well as the density of the air. Interestingly, wind can reduce the range quite significantly; a blog post by A Better Route Planner explains how wind conditions affect vehicle range. A headwind of 10 m/s can reduce highway range by about 19%, while a sidewind of a similar strength has a slightly lesser impact. On the other hand, a tailwind can boost range by 6-7%, but it needs to be direct for the best effect. Air density, which influences aerodynamic resistance, can be calculated using temperature, air pressure, altitude, and humidity. For instance, when the temperature drops from +35 °C to -25 °C, air density increases by 20%.
The rolling resistance of tires is mainly affected by water and snow on the road surface. Ambient and road temperatures also influence tire performance. Measurement studies in a report by VTI show that rolling resistance increases linearly with the amount of snow, but this increase heavily depends on snow density.
The effect of snow on the road surface on rolling resistance. Results of measurements with ASTM tires.
Adapted from VTI rapport 971A, 2021
It’s clear that many factors affect your EV's energy consumption, from the way you drive to the weather outside. Your vehicle's powertrain and aerodynamics play a key role, but your driving habits can make a real difference too. Being mindful of how you accelerate, brake, and even plan your routes can help maximize your range. Weather, whether it’s a hot sunny day, a chilly wind, or snow-covered roads, also impacts your car’s efficiency. By understanding how things like temperature, wind, and road conditions influence your EV, you’ll be better equipped to manage these fluctuations and get the most out of every charge. Happy driving!
