as even a very unlikely "worst case" of driving +650.000 miles battery pack capacity (>70%) would leave you wit more juice in your pack than Nissan guarantees.
The problem is that people are buying the car with *specific trips in mind*. If the car's range drops below what you need for *your specific trip*, then for you *the car has broken*, and it's not covered by warranty.
This makes it very important for buyers to know in advance how long a trip they can *reliably* take. I just assumed that my reliable range after 10 years would be 70% of 80% of the EPA range (terribly pessimistic assumptions), and that is about 148 miles. Thankfully, that's enough for me.
*But a lot of people are buying the car assuming that they can get longer ranges than that*, and they will be justifiably upset if (a) they don't get the range they need and (b) there isn't a fix for it. It's important for Tesla Motors to set expectations a bit on the low side, and instead they're setting expectations too high (how long were they advertising 300 mile range for?). It's OK if outside forums like this are more optimistic, but Tesla staff should be saying "Expect to get only 80% range after 10 years".
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The problem I have with low balling is everyone is going to focus on that low number, i.e. "Tesla packs will only have 70% capacity after X years and X miles".
Deal with it! It's not a problem. It's true that overadvertising gets more sales, but that's not a reason to do it!
It also creates hurt, upset customers who will not come back and who will give you bad word of mouth. I've dealt with this with more companies than Tesla...
Underpromise, over-deliver. That's the way to get satsified return-customer word-of-mouth.
There should be a lowballed, warrantied range. Tesla can say outright "We find that 90% of our customers, who drive carefully and do not range charge, get better range than this." But the lowballed warranty range is the necessary caution to give, to avoid having customers who feel cheated.
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I feel somewhat responsible for this thread because Kevin asked about the Model S warranty and I responded with the link to the PDF and said that it doesn't.
I think it's pretty clear from the warranty that Tesla is not promising to warranty any battery for range loss. That doesn't mean they can't do so out of goodwill (and from what I've read here it's clear they have done massive amounts of goodwill work in other areas that doesn't qualify under their warranty).
They kind of have to do warranty repairs for severe range degradation -- implied warranties of fitness and marketability cannot be disclaimed. The thing is, who wants to get into the weeds of how much degradation makes the car "unfit"?
Most of us would agree that a 95% loss of range (within the warranty period) would require a warranty repair regardless of what the written warranty says; most of us would agree that a 5% loss of range wouldn't. It's much easier for everyone if there's some sort of well-defined line, though.
Should Tesla cover range degradation? I don't know. I think it might be hard to define what they would cover and not cover due to the variety of ways the battery can be used. Being more up front about the warranty might force them to do something if it hurt sales. But I think in the end the company would be stronger for it. I would no longer have to tell people they should realize that the range is not warrantied.
That's what I think, too; I just think it would create happier customers.
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AFAIK Tesla's "internal policy" is that their warranty doesn't cover "natural degradation" but it does cover "unnatural degradation" bc that signifies a defective battery pack and the number they use is that if the battery goes below 70% capacity within 8 years that is unnatural and would qualify for replacement.
If this were well-publicized in advance of sales that would probably be very helpful in avoiding upset customers.
