The LR RWD has a constant of 234Wh/rmi (and always has - the 310->325 unlock unlocked capacity AFAIK). SMT says FPWN of 77.8kWh. It's possible that your early vehicle never quite had this capacity (though some vehicles probably did). That works out to 77.8kWh/234Wh/rmi = 332 rated miles. However, the degradation threshold (where degradation starts to show) is 76kWh. That works out to 76kWh/234Wh/rmi = 325rmi. Basically the display was limited to 325 rated miles, even if you started with the equivalent of 332, in energy terms.
So, SMT is correct; you have about 13.9% loss. However, to be clear, we don't know exactly where your pack started (that value SMT reports is a hard-coded value associated with the pack and does not reflect exactly where your particular vehicle started).
It's possible you have actually lost as little as 12% if you actually started closer to 76kWh. (The only way you'd know this is if you had SMT right at the beginning.)
I think it is likely your pack started around 77-78kWh. But the data on those early packs early in their life is very sparse, so there's really no way to know for sure.
14% loss after 3 years and 25k miles seems pretty normal, but possibly slightly on the high side. It's actually a pretty great result. My 2016 Chevy Spark has lost about 35-40% capacity at about 24k miles (equivalent to about 75k on the Tesla I suppose) as mentioned earlier here. The plus side is it has not caught on fire spontaneously.
I have a 2019 LR RWD, 4/19 build, the last of them built before they went away, 324XXX VIN.
I started running SMT after about 6 months of ownership and 6,642 miles. My NFP at that time showed 77.6. I bounced around a bit, 77.4, 77.5 but the last recording of 77.6 was at 7,871 miles almost a year after picking up the car. The Energy Buffer setting when new was 3.5. It dropped to 3.4 at 10,339 miles in Dec. 2020. In June 2021 at 12,100 miles it dropped to 3.3 and has stayed there since.
Today I'm at 13,900 miles and showing a NFP that has been bouncing around 72.9-73.3 for the past few months.
For the first year of the car's life it stayed at 50% SOC between trips. I have a Nissan Leaf I use as daily beater for errands and to go play golf. The Model 3 is the trip/weekend car. I would charge the car to whatever SOC I need to stay in the middle of the pack as much as possible. Lots of 60-40 or 60-30 SOC trips.
When I took the car on its first 1,500 mile road trip I could still stay between 70-30 SOC for most stops thanks to the Supercharger network.
I've charged to 90% maybe 3-4 times. I've never been lower than 15% and that was just to let the battery sample a low SOC. That brings up
this article I've been following the last 8 months. It argues the car needs to sample various SOC levels for 4-6 hours to properly calibrate the BMS.
I've usually let my car sit for a few hours when returning home, but started giving the car time to sit at a higher SOC for 4-6 hours before leaving on a trip giving the BMS time to sample.
My car is still showing 312-315 miles of rated range in SMT at 13,900 miles. Curious to see if battery degradation will level off or slow down now. I'm showing about 6% capacity loss and and about 3.7% range loss compared to 325 miles of rated range.
Not sure if I'm lucky with a "good" pack or how much I've helped myself with good battery care. My conservative approach is to stay between 70-30% SOC as much as possible and continue to store the car between 35-50% SOC. The EPA doc for the Model 3 battery calls for 15-50% SOC for long-term storage. I also take that to mean 15% is as low as I will try to go before recharging while on trips. But there will be times I may need to go to 100 or 0 to make a trip work and will charge or discharge as needed. But otherwise I'll ignore Tesla routing suggestions to go from 90-10 is I can insert another SC stop in between to stay between 70-30. I'm sure this will also be kinder to the battery when Supercharging.
Any thoughts Alan or Lastgas?