209 original miles from the charge. Drove 72 miles in 2 days would have made mileage on perfect conditions
= 137
However car shows 87 Current miles?
Am I overthinking something? Honestly a little confused in your reply.
So 44 miles missing
Yes, you're overthinking things.
Phantom drain is a specific thing - it's the car taking energy when it's parked. Could be from sentry mode, from an app like TeslaFi pinging your car and keeping it from sleeping, from cabin overheat protection, or even just from temperature changes causing the Battery Management System to update its estimate of the total and current capacity of the battery. Or it could (theoretically) be a bug or issue with your car. It almost never is. It's generally behavior based.
We need to take a step back from that - your issue is almost certainly that your consumption doesn't EXACTLY match the EPA rating that the car shipped with. When you set the display to Miles/Distance (209, 87 etc) rather than Energy (%), the car just takes the estimate of battery capacity, multiplies by the original EPA consumption rating, and gives you a number of miles. Almost no driver hits that number, and certainly not consistently. The "Miles remaining" display on the battery indicator is, in my opinion, misleading and useless. Driving in cold weather, driving faster than ~60mph, driving up hills, driving in hot weather, accelerating and braking often - all of these things can lead to your energy usage being (much) higher than the EPA estimate, so you will typically see 5 miles of driving take 6, 7, or 10 "miles" of energy from the battery. You should also make absolutely sure your display is set to "Rated" and not "Ideal" (that was an option on older Model S and gives a wildly useless estimate of range in perfect conditions).
The best way to monitor usage is to use the Energy app in the car - that displays your recent consumption over the last 5, 15, or 30 miles, and will show the "Rated" line (the EPA rating) and whether you're above or below it. Your car may have been rated at 300Wh/mi (I don't know - mine is about 280), but you might find that your driving style and climate have you using 330Wh/mi - that would be 10% over, and driving 70 miles will take 77 "miles" from your range.