Great write up
@Baluchi, and your data tracks mine. I have a 2022 LFP car ("RWD" model with 60kwh battery), delivered Nov 13th. Since it is only a few days from now, I'll go ahead and post my 6 month update so people can compare the two.
I've driven 6,143 miles, show a lifetime average of 215 Wh/mile, and full charge shows 269 miles (vs 273 new), about 1.5% degradation - assuming that is real and not just a calibration error. Like you I only charge to full once a week unless my needs dictate otherwise, and L2 charge at home, with the exception of a handful of supercharging sessions.
On longer trips I've seen 220 Wh/mile averages, but I should note I live in a very large metropolitan area with tons of traffic that extends over 100 miles in every direction. So while I routinely hit 70-80mph, I also spend plenty of freeway time moving slowly in traffic at stupid slow speeds.
In an effort to determine real highway efficiency, I set out at 2AM last night and made 70mph runs up and down the freeway on AP with no traffic near me. Temp was 50F, tires at 49PSI cold, AC off, and I clocked 15 miles in each direction, measuring the consumption with the trip meter. Based on my one night of testing I show 245 wh/mile average consumption at 70mph. I plan to repeat this test several more times to see how consistent the number is, and then make some aerodynamic tweaks to see if I can improve on the number.
Oh, and a simple test for brake rotor drag - drive around your neighborhood for 10-15 min without ever touching the brakes (regen only). Then check the rotors - if they are cold then you have no drag. If they are warm/hot then you have pads dragging and that will reduce efficiency.