While your average fossil-fuelled car owner may not notice it, every single car on the market today suffers reduced fuel efficiency in the winter, caused by denser air, inclement weather conditions, increased rolling resistance with the road, and higher user of the car’s heating and air conditioning system.
By far however, electric cars suffer more than any other type of vehicle in the winter, caused by extra use of on-board heaters and the material properties of the electrochemical batteries which provide the power needed to move the cars along.
For hardened electric car drivers with several years of winter driving experience under their belt, winter conditions rarely pose a problem. For would-be electric car owners however, the question of how much range is affected in winter is one that is often in the front of their minds, despite a large number of electric car owners around the world living their daily lives without a range-related problem in electric-car friendly winter wonderlands like Ontario, Canada, Norway, and Finland.
Since each electric car on the market today is affected to a lesser or greater extent by winter weather as a consequence of its specific design, figuring out just what affect winter can have on an electric car can be difficult to figure out. So when the owner of a particular car does their own in-depth analysis of winter driving range in their plug-in car, it’s always worth sharing.
Enter Rob M, a blogger over at popular Tesla fan sites Teslaliving.net and Teslarati. An engineer by trade and a resident of New England, Rob has seen some particularly brutal temperatures this winter, giving him the perfect opportunity to track his car’s winter performance over the entire month of January.
Recording the rated range of his Tesla Model S at the start of every day and again at the end of the day, along with the odometer readings, miles driven, energy used, and rated miles used, he was able to figure out just how much of an impact his ten month old Model S 85 kWh was experiencing. To improve the analysis, Rob also recorded the average temperature for each day recorded, enabling him to plot range loss versus temperature.
The results, explained in full in this Teslarati post show on average a ten mile drop in real-world range for every ten degrees Fahrenheit drop in temperature.
Given the consistent battering of the north east this winter, he said that equated to an average drop of 40 percent or more during the winter, equivalent to a real-world average range of just 143 miles between charges from a 90%, non-range mode charge. That’s far from the 265 EPA-approved miles of the Model S in temperate weather.
As you might expect, Rob says snow and ice on the roads affects range even more, so if it’s cold and snowy, you need to be really prepared for a range reduction. Given that the Tesla Model S is one of the more capable cars when it comes to keeping its winter range, we’d suggest other electric cars could suffer even more in similar conditions.
In a previous post, Rob says there are other things affected by the cold, including a marked reduction in regenerative braking capabilities.
Here at Transport Evolved, we’ve noticed all of our staff cars — eight in total — all suffer varying degrees of electric range loss in winter due to colder weather, with cars that have no battery heating suffering more than ones with active thermal management.
But in our experiences, the best way to ensure that electric car range doesn’t drop in winter is to make use of cabin pre-conditioning as much as possible, and to ensure that cars are regularly driven to prevent their battery pack temperature falling too low.
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