We returned our S90D on 6/4/19 with 44,817 miles under the Resale Value Guarantee.
I maintained complete data regarding how much and where I charged the car. We consumed 19,835 total kWh. That's a rate of 443 Wh/mi delivered to the car. The car's trip screen showed our consumption rate as 342 Wk/mi. We drive fast on our travels, typically 75-80mph, and our most frequent destination Mammoth includes 8,000 feet elevation gain with some recovery of that on the return home.
63% of our charging was at home, 8% at the local Burbank supercharger and 29% at road trip superchargers. Free supercharging saved us $1,700. Home charging cost 6.3 cents/mile and I estimate that we saved $5,400 vs. a 20mpg gas car over those 38 months.
The above shows battery degradation from 294 rated miles in April 2016 to 272 rated miles in June 2019. That's 7.5%, which seems normal for a 90 but high for other Tesla batteries.
Our battery was charged to 95+% frequently on our travels, 26x at home before departure and 40x at superchargers. At home the default charge rate was 70%.
Before buying the car I downloaded a chart from a S85 owner on this forum and used it to estimate real world range based upon speed, temperature and altitude change, and how long supercharge stops might take. The real world range achieved averaged 105% of the estimates, though there were some underestimates due to high winds, erratic speeds etc.
I always monitored charge rate for the first 5-10 minutes after we plugged into a supercharger to see that we were getting a reasonable number, but once we were I didn't pay much attention to the exact taper curve. I did notice that out max rate through 2018 was 105kW but that it was only 93kW on 8 charge stops in April. Thus I assumed I was now one of the "nerfed" 90 battery owners.
For our final May trip to Mammoth, Death Valley and Las Vegas, I monitored the taper curve and compared it to the on for the 85 which I had downloaded in late 2015.
In May the pattern of charge rate was different than in April. It was about 90kW at 10% and rose gradually to 100kw at 45%, then started to taper. I observed this exact pattern at both Lone Pine May 25 and Beatty May 29. The downloaded curve for the 85 has a faster charge rate of 115kW at low SoC but its taper starts at 20% and its rate is lower than mine from 40-75%
While I recorded rated miles added at all 143 of my supercharge stops, I had recorded time spent supercharging at only 40 of them. Those sessions started at an average of 14% SoC and finished at an average of 74% SoC. The curve differences above/below 40% SoC offset so my actual charge time averaged 98% of expected over those 40 sessions. In only 3 sessions did I have materially slowed charging speed due to being paired with another car. There were other paired occasions but the other car was well into its taper so I was charging normally. In summer/fall 2017 there were a few cases where the supercharger was throttled to 60Kw by heat, but when I saw that I moved to another stall and always found one operating properly.
