[mlyle]

It's 5 years, which is in the ballpark of a typical timeframe for ownership of a new car.

Yes, as cars get older they get less reliable. This is likely to be true of the Tesla, too.

The number is kinda baked into the real resale value, anyways. A good part of what subsequent buyers are willing to pay is based on their inferred operating costs.

[xbmcuser]

The main assumption everyone makes is that Tesla/electric cars will be more reliable compared to ice cars as they have fewer moving parts. Electric cars haven't been around long enough yet for long term evaluation.