In response to an independent range test, Tesla has claimed that EPA range on its vehicles can be achieved by draining the battery beyond the displayed range of zero miles.
Last month, we reported on Edmunds conducting independent range tests on a group of EVs to compare them to their EPA estimates.
The results showed that Tesla is using the more optimistic versions of its EPA-estimated range in its advertising compared to other automakers.
Now Edmunds has released a follow-up report in which they claim that Tesla reached out to them after their test to claim that they should have taken into account the “buffer” that comes after the displayed range reaches zero miles:
Needless to say, Tesla was unhappy with our test results and we received a phone call. Tesla engineers questioned our figures. They argued that we had underestimated the true range of their cars because our test ran at zero indicated miles instead of stopping.
Tesla argued that even when the indicated range reaches zero, there is still a safety buffer. Engineers calculated that if you added this buffer, the measured distance to when the battery was depleted, your cars would match the EPA results.
It’s surprising that Tesla claims that, since that’s not how people use their electric vehicles.
Edmunds put Tesla’s claim to the test and tested three Tesla vehicles, as well as two vehicles from other manufacturers, to see how many miles they would travel after the displayed range reaches zero.
Here are the results:
That test was at 65 mph, but they also ran the test with a cycle closer to the EPA test cycle:
Edmunds says they were told by Tesla engineers that “the buffer cannot be set to exactly one number at a time; it will change based on external conditions, driving profile, etc.”
By adding those buffer results, only two of Tesla’s vehicles actually hit their EPA-estimated range.
Our response to Tesla’s dismay with our initial results is that, yes, two of the automaker’s vehicles can match EPA’s range estimates in Edmunds’ EV range test. But that’s only in specific circumstances and when driving each vehicle beyond the stated zero-mile range.
However, they also admit that range tests can be affected by many external factors.
As I said in my original article on the Edmunds test, no range test is perfect, but I think the comparison in the report is what most people would experience and what I experienced myself, having driven almost every vehicle from the list.
I’m surprised by Tesla’s response to the test and I think it’s a bit strange.
This is a perfect example of why I think it is a mistake that Tesla has closed its PR department because I would like to understand better what they communicated to Edmunds.
In the old days, if Tesla disagreed with Edmunds’ methodology, they would have issued a clear official statement explaining the situation, and I doubt it’s as simple as not taking the battery buffer into account.
It sounds like some Tesla engineers named Edmunds here, but we only know the story from the Edmunds side.
Anyway, if anything, this shows that we need better ways of looking at the range and efficiency of EVs, because right now, it’s all over the place.
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