In the grand scope of automotive history, modern electric cars haven't been on the road very long.

Yet they've already demonstrated considerable staying power.

At the Electric Drive Transportation Association conference in Indianapolis, PlugInsights Research (via InsideEVs) unveiled new findings indicating that--three and a half years after the December 2010 launch of the Chevrolet Volt and Nissan Leaf--drivers still love their electric cars.

PlugInsights calculated a Net Promoter Score (NPS) for a handful of plug-in models. (The research firm is part of Recargo, owner of the PlugShare app for locating charging stations.)

2014 Nissan Leaf

2014 Nissan Leaf

The NPS concept is used in several industries to gauge consumer approval of a product. A score is determined by asking customers whether they would recommend a product, subtracting the number that wouldn't ("net detractors") from the number that would ("net promoters'), and tracking changes in the result over time.

The results included an NPS of 94.2 for the Tesla Model S between delivery and the first 11 months of ownership, which actually rose to 96.6 percent between 12 and 23 months of ownership.

The Chevrolet Volt also scored well. Its NPS increased from 79.2 between delivery and the first 11 months of ownership, to 85.2 percent after 36 months.

However, the Nissan Leaf's NPS dropped from an initial 66.8 percent to 49.8 percent.

PlugInsights attributes this to "battery degradation" issues, and notes that the Leaf's NPS "is still excellent when compared to [those of] the top-marked auto brands."

Researchers add that this love of electric cars isn't simply a passing fling for most customers.

Tesla Model S

Tesla Model S

The report notes that at least 32,250 electric cars will be three years old or more by May 2015, rising to 95,716 by the following May--suggesting that many drivers will stick with them for at least the length of an average lease.

Of about 900 surveyed owners who face the choice of acquiring another electric car or returning to internal combustion, 96.9 percent said the top choice for their next car is another battery-electric vehicle or a plug-in hybrid.

PlugInsights didn't break down its results by region, but a separate study showed continued enthusiasm for electric cars in the state that has more plug-in vehicles on its road than any other: California.The 2014 edition of the California Green Innovation Index (PDF)--which tracks the economic results of the state's pollution-control policies--found that from 2011 to 2012, the number of electric-car registrations rose 20 percent, to around 24,000 total vehicles.

California is already known as a haven for electric cars, but its next challenge will be expanding adoption beyond hardcore fans and early adopters.

To that end, Governor Jerry Brown signed six bills to promote electric cars last fall, and the Golden State is part of an eight-state coalition that hopes to put 3.3 million zero-emission vehicles on its collective roads by 2025.


Follow GreenCarReports on Facebook, Twitter, and Google+.