The electric SUV only managed to drive 47% of its WLTP range in Danish tests conducted at 4˚C (39˚F).
Even when compared with the lower EPA figure there is a significant difference.
Toyota is investigating the issue and a preliminary conclusion is expected next week.
Cold temperatures are known to be unfavourable to the range of electric vehicles, but the effect is worse on some models than others.
According to tests conducted by the Danish website FDM, the first modern Toyota EV, the bZ4X, only managed to drive 215 kilometres in Dual Motor configuration when the temperature hovered around 4˚C (39˚F).
Given that this model is advertised in Europe as having up to 461 kilometres of range, this represents a 53% decrease in driveable distance.
The more efficient single-motor version doesn’t do much better either, with a real-world range of 246 kilometres versus the advertised 504 kilometres, a 51% difference.
These results are not a one-off since they are in line with what other tests that took place in Northern Europe have found.
Part of the explanation for this result is that Denmark, and the rest of Europe, use the WLTP standard to measure EV range which is known to be less accurate than the stricter EPA method used in North America.
Even so, the dual-motor version of the bZ4X is given for 367 kilometres and the single-motor variant should be able to cover 406 kilometres on a charge according to the EPA, which is still quite far from the test results.
Of course, given that the test was conducted at a constant 110 km/h and with vehicles equipped with winter tires, the real-world results were bound to be lower than the official figures, but this difference is the largest among EVs tested in similar conditions by FDM.
Another factor could be that the battery seems to have a much lower useable capacity than usual since the testers say the car only had about 60 kWh of useable energy in a battery that should hold 71,4 kWh.
This could have been done deliberately by Toyota in order to protect the battery and extend its service life, but the automaker hasn’t said so.
Contacted by the website, Toyota began an investigation into the issue and is expected to communicate a preliminary conclusion as soon as next week.
Since both vehicles are mechanically identical, it is almost certain that the Subaru Solterra will exhibit a similar difference between its actual and its advertised range, although this has yet to be confirmed.