2018 is looking to be the greenest year yet for the auto market, according to new data from Edmunds, the leading car shopping and information platform. Edmunds analysts project that overall market share for green vehicles (EVs, plug-ins and traditional hybrids) will reach 4.4 percent in 2018, compared to an estimated 3.2 percent in 2017. Edmunds also predicts sales of plug-in vehicles will double in 2018 as compared to 2017, outselling traditional hybrids by the end of next year.

"Even if Tesla doesn't meet its full production commitments for the Model 3 until midsummer, 2018 will still be a hallmark year for green vehicles," said Jessica Caldwell, Edmunds executive director of industry analysis. "The price of batteries is coming down, EV range is rising, and shoppers will have more choices than ever. However, the lower end of the EV market will feel pressure once federal tax credits start to wane toward the latter half of the year, which will give the first indication of how ready the segment is to stand on its own."

Edmunds predicts a total 16.8 million new vehicles will be sold in 2018, which is down from the expected 17.2 million new vehicles in 2017.  While this would be the second straight year of decline for the auto market, sales at that level still represents a healthy position for the industry. Even though green cars will have a big moment in 2018, sales volumes will be largely driven by the continued growth in popularity of trucks and SUVs.

"There's a lot for automakers to feel good about heading into 2018, but as sales decline the battle to retain market share is going to get intense," Caldwell said. "Everyone is going to be fighting for a piece of a smaller pie, and it's going to be very tempting for companies to hike up incentives to keep sales strong, even though production is expected to be better aligned to demand."

"From a product perspective, many auto brands, particularly in the luxury segment, will be phasing out slow-selling passenger cars in favor of in-demand small SUVs. And the rise in green car sales is really just a precursor to what OEMs have in the works for the autonomous vehicles promised for 2019 and 2020. 2018 will be a year of right-sizing for the present while putting some of the critical building blocks in place for the future."