I have a 2018 Bolt EV.
I have a 2018 Bolt EV. bought in Nov 2018. when i first bought it full charge was about 238 miles. the first day to work in commuter traffic i learned about the hilltop reserve. I always keep hilltop reserve on as i commute 72 miles a day in stop and go traffic and this allows me to regen right from the house ( limited me to about 215 mile capacity). now 2.5 years and 31K miles later I regularly can only charge to 160-165 with an occasional 180 mile capacity ( i still have hilltop reserve on). I live in Phoenix and the maximum charging capacity I can get is between Dec and Feb. In the summer the A/C can use 5-6KW ( tested at a light with a/c on max and off, delta in usage). I haven't taken any actual numbers for capacity. but if i use the 238-180/238X100= 14.7% change since new. I need to take capacity number each month and average monthly temp to correlate the temperature dependency.