Is that your 90%? My S90D gets close to that when charging to 100%, about 241 (388km) when charged to 90%. Looks like I'm on the very low end of where it should be (~9% degradation for about 35,000km 1 year later).
Yes, my 100% is 298 miles. I got lucky in the battery department.
I've sometimes said I have good "carma". I bought a used Chevy Impala with 70,000 miles on it that had been a company car, had been driven off road a fair bit, and I put another 70,000 miles on it with few problems. The only major problem was the water pump housing split open when I was sitting at a traffic light. But there was a service station on the corner and they had no cars in getting any work. It was also only three blocks from home.
After that I bought a Buick Roadmaster new in 1992 and drove it until I bought my Model S last year. Except for some carpet wear, the interior looked new and my mechanic had said he wanted to buy it because it was in such excellent mechanical condition, but unfortunately the car outlived him. He was a really nice guy too, everyone who knew him was crushed when he died of a heart attack.
So far the only real issue I've had with my Model S has been the headlight buzz a lot of the refresh MSs get and that didn't really affect anything other than it was annoying. The multipattern seats were terribly uncomfortable and I replaced them with next gen, but that was more of a design issue than anything going wrong.
I don't know if this car will last as long as my Buick did. That was kind of exceptional for any car of any make. In 10 years or so I might be thinking about an upgrade but probably because this car will be like a 1990 portable phone today, hopelessly obsolete.