Think of it this way. If this actually impacted range in any meaningful way, dont you think tesla would simply install a spoiler on every car? They dont, because it doesnt.
I think it might be a more complex issue than their desire to optimize all their cars though… There’s also the aspect of “trim levels” and deleting the spoiler must save a lot of money when you’re talking about units numbering in the hundreds of thousands per year, and I think it’s been shown that Elon doesn’t mind thinking in terms of cost saving deletions vs capabilities with things like removing mobile chargers, matrix headlights, sensors, glass coatings, even floor mats etc. Since we pay a significant amount more for the performance trim, that additional cost is mitigated.
If adding the rear spoiler somehow involved no cost. Then I’m certain Tesla would have them on every trim level of car, but it may be more accurate to think in terms of Elon considering, “Yes, the spoiler improves range by 1% on average, but putting them on every car costs me 9 million a year”
It’s like the situation where that 1% is worth FAR more to the individual user than it is to Elon. His “loss” is worth more than the effect of your “gain”
I could be totally wrong about all this, but I often see issues similar, when one approaches the question with the values of an individual consumer, instead of from the perspective of a manufacturing giant; which makes sense, we each perceive the things we know. Maybe that’s why some of Elon’s decisions are so confusing to us
But on the use of a spoiler. It CAN have an effect on drag, and thus range, but it’s primary function is not to create “Downforce”, but to reduce “Lift” by causing the airflow to separate more cleanly from the rear of the car at speed instead of curling down the rear of the car and getting underneath the rear, lifting the rear and reducing traction. Drag reduction is simply a byproduct of the primary function. It’s called a spoiler because it “Spoils” or decreases lift. If it was primarily used to cause downforce, it would be called a deflector, or a control surface.