Confused About EPA Range vs Rated Consumption

[Master_Aryon]

I’ve been driving a Tesla Model Y for a bit now, after two years with a Model 3, and I’ve noticed something that doesn’t quite add up when looking at range calculations. The efficiency on my Y is great, actually better than my old Model 3 in certain conditions, but when I try to do the math on EPA range versus rated consumption, I’m scratching my head.

Here’s the situation:

• I drove 200 km at 120 km/hr in near-freezing temps and logged 200 Wh/km, which I think is pretty decent.
• The rated consumption for the Y is 170 Wh/km, but with a 75 kWh battery, that only gives around 460 km of range, not the 520 km the EPA rating claims.
• For the Y to hit 520 km of range with a 75 kWh battery, the average consumption would have to be closer to 140 Wh/km, which seems way off from the rated 170 Wh/km.

I get that EPA ratings are based on mixed driving cycles and ideal conditions, but how does Tesla reconcile the 170 Wh/km rating with the EPA range? Does anyone know if there’s a different calculation or assumption being used here? Or am I just missing something obvious?