Is this true? My understanding is that EPA ratings are provided by the manufacturer based on dyno test results with appropriate drag coefficients, on individual articles - it is not simulated. That being said I am not clear on the SR EPA vs the SR+.
Basic Search | Document Index System | US EPA
There are full tests for LR RWD, AWD, MR, and SR+. So far I see no test documents for Tesla 2020 models.
Previously Performance was the same as AWD due to low take rate and otherwise was the same vehicle. Performance 18” also can no longer be combined with AWD presumably because it has a different drive unit. Rating is better than AWD anyway, so they call it out.
Probably in 2020 they could lump the Performance PUP in with Performance 18” because it is probably low enough take rate, but out of basic decency it appears they are not going to do that.
In fact, they call out Performance 20”, 19”, and 18” individually in the ratings now. If you read between the lines I think you can conclude that all the Performance models are also getting an efficiency boost (not surprising), but it is difficult to compare apples to apples except in the 18” flavor.