I bought my M3 Performance in August. I started keeping track of charging with TeslaFi at 1,244 miles. Charging most of the time to 90%, range after charging was 308 to 310 miles. At 1,700 miles, range gradually declined to 302 to 304 until I reached 1,946 miles. I'm now at 2,390 miles with no further decline. The decline doesn't correlate with a software update nor temperature.
Tesla increased the range on the LR from 310 to 322 miles but left the Performance at 310 miles. I wonder why the Performance range didn't also increase.
Thanks for everyone's reply, input, experience and analytics. I'm a simple guy so put it in 6th grade math for me- Should I be concerned, or should I just ignore, my current 100% charge range of 304 miles, that used to show 310 miles every time I charged to "100%," for the past 12 months? I use my Model 3 for work commute, have only taken one long road trip to SoCal (and took the battery charge down to 7% before recharging to 90%, due to Tesla recharging locations), reside in the Bay Area so temps are very mild throughout the year.
I'm so sorry for the very poor sentence structure and multiple misplaced modifiers...