That cabin pre-conditioning really only works when at home and plugged in. This won’t help when leaving work (if you don’t have a plug), leaving a store or something where the car dropped to ambient temps (30+ minutes in winter), apartment/condo dwellers, when leaving a hotel without a plug, or anywhere else in the real world without a plug. Again any extra efficiency is great, but if you’re heating up hundreds of pounds of mass for an HOUR you’re burning a lot of energy before even rolling a mile. I feel like Tesla could tweak the Model 3 via software to heat the battery when plugged in and preconditioning (if temps are below 30F or something) to heat the mass of the vehicle. I thought Model 3 harvested some heat from the motors or pack coolant loop but even if it didn’t, if you had full regen because of a hot pack then you might recover enough energy initially to offset that heating.
Again, I think any improvement is good, but please adjust your expectations for a slight improvement, not “practically no penalty” for using heat when you actually need it, 30F and below. The Model 3 has amazing heated seats, some of the most powerful and I think down to 50F most people probably are fine with just heated seats or maybe a small amount of heat added.
I look it as the same as someone that gets the most efficient heat pump for their house expecting to see energy usage in January drop by half or more and then is puzzled when resistance heating is used because it’s 25 F outside... this is even more true when it’s an old house with poor insulation, even when at temp a heat pump might not be able to keep up with the heat lost due to poor insulation. I doubt the Model Y has much extra insulation compared to the 3. Turn the heat off in your 3 when it’s 20 to 30F outside and watch how fast the cabin temp starts to drop. There is a large heat demand to maintain...
Trust me, good on Musk & his engineers, but adjust your expectations.