Posted on July 10, 2018 by Charles Morris
A Better Routeplanner, a blog that discusses EV trip planning and ways to maximize range, has amassed an impressive database of driving data from Tesla owners (you can donate data too, by logging in to MyTesla in ABRP and checking “Share Data with ABRP”).
Above: Tesla's Model S (Twitter: Tesla)
Published specs are all very well, but it’s always valuable to be able to compare these to real-world data from vehicles that are actually on the road around the world, and that’s what ABRP has set out to do. ABRP’s database currently includes 805 Teslas, which have logged some 2.6 million data points to date, representing about 217,000 miles of driving. Data guru Bo has crunched the numbers to generate some interesting charts that correlate range with speed and temperature.
In an earlier blog post, ABRP correlated power consumption with speed. As the chart shows, individual data points are all over the map, but the overall trend is just what you’d expect: higher power consumption at higher speeds. At 65 mph on a flat road, the median Model S consumes about 20 kW. That’s a lot of power - the large and powerful Model S is not the most efficient of EVs - but it’s far less than any fossil vehicle would burn. ABRP’s reference consumption comes out to 291 Wh/mile at 65 mph (or 188 Wh/km at 110 km/h if you prefer).
Above: A look at Tesla Model S power consumption vs. speed (Source: A Better Routeplanner)
A more recent post addressed the question of how range is affected by outside temperatures. ABRP has now collected data all through the (northern hemisphere) winter and the beginning of the summer, so there’s enough data to compare the energy consumption of the Model S and Model X in different temperature ranges (Model 3 owners have not provided enough data yet).
Above: Consumed Power, Range, Speed, and Temperature data from 805 Teslas (Source: A Better Routeplanner)
Analytical minds will want to go to the ABRP site to get the details of Bo’s methodology, but the charts tell the story: cold-weather driving generally consumes a lot more power. The main reason for this is surely cabin heating, which appears to consume around 5-6 kW at very low temperatures. However, there are probably also other factors at work: battery capacity is known to be affected by extreme temperatures, and cold weather also means snow, rain and ice on the road.
ABRP found that “while it is unclear exactly what the source of higher consumption at lower temperatures is...it is very clear that on average, lower temperatures lead to significantly higher power consumption and therefore also less range.”
According to ABRP’s real-world data, the maximum range of a Model S at temperatures below freezing is about 22% less than at temperatures above 20° C (68° F), and almost exactly the same range reduction was found for the Model X. Stay tuned to ABRP to find out how cold temperatures affect Model 3.