GRA
Well-known member
How all Leafs are doing on a worldwide basis is statistically irrelevant to U.S. owners living in the desert southwest, and other parts of the country that see prolonged periods of summer highs above 95 F, possibly lower, and similar periods with elevated nighttime lows. We already knew that if you live in an area with a maritime coastal climate such as the PNW west of the Cascades, Japan, or NW Europe, the battery shouldn't have many problems. What matters to U.S. Leaf owners is how the batteries do where people live _here_, where a large area of the country has a climate the Leaf's chemistry and lack of a TMS is ill-suited for and where Nissan nevertheless decided to sell the car without warning potential customers.OrientExpress said:I disagree. The confidence would be correct IF the sampling was truly random. But PIA's survey is volunteer based and advertised in places where Leaf owners with problems are a bit more likely to respond than owners with no problems. So I would not have such real confidence even at 600 responses.... not unless Leaf owners are chosen from random.
That is true that the initial sample is somewhat biased given the recruitment methods used, but that bias will even out to be more representative of a universal sample that was chosen randomly when you reach an optimum sample size for a given universe. For the global universe of LEAFs in service, than minimum number is 600.
It has been the ridiculous and, judging by your trotting out of the same empty argument again, continuing attempt by Nissan to bury hot climate U.S. battery data among either total U.S. or even world-wide battery data to make the data look better that has been among Nissan's most cynical and dishonest massaging of the numbers (along with the claim that Phoenix cars weren't showing significantly higher degradation, but only eventually stating that was based on an annual mileage of only 7,500 vs. 12,000 everywhere else. Yeah, that's really honest, especially when Nissan is leasing the car for 12,000 miles/year in Phoenix rather than 7,500).
To a potential customer living in Sacramento or Palm Springs or Phoenix or Dallas or Oklahoma City or Miami, the fact that the battery is doing fine in Seattle or Portland, let alone Dublin, Kobe or Brussels, is totally irrelevant. They aren't going to be driving or parking the car there, and that's akin to arguing that because a group of people have jumped off the Empire State building and are evenly spaced out on the way down, on average they're at the 50th floor and thus everything's fine.
I've seen it attributed to many people in addition to him, but it sounds to me like something Mark Twain would say: "There are three kinds of lies. Lies, damned lies, and statistics." Nissan's continuing attempt to use worldwide or all-U.S. data in order to persuade people to draw the conclusion that there's at most a minimal battery problem in hot weather is a classic example of 'statistics'. It isn't going to wash.
If Nissan hopes to convince us that high temps aren't a problem, and claims to be collecting all this battery data on every car whenever they have their annual battery check, let's have them show us the separate results of the data for just four states, out by state: Wa.; Ca.; Tx.; Az. No adjusting mileage or other gimmicks, just the same info that has been put together by owners here, but on a voluntary (and thus inevitably skewed) basis. For that matter, just show us the data for every car in Arizona; we already know the number is far higher than 1% there.