General Motors (GM -0.05%) said it delivered 3,227 Chevrolet Bolt electric vehicles (EVs) in the United States in December. It was the best monthly sales total yet for the Bolt -- and the ninth month in a row in which the Bolt's U.S. sales were up from the month prior.

It wasn't America's best-selling EV last month, as it lost out to Tesla's (TSLA -3.55%) now-traditional quarter-end sales push. But the Bolt's December sales were good enough to put it over 20,000 sold for the year -- and enough to outpace Tesla's Model X. 

A black 2018 Chevrolet Bolt EV parked on a sunny beach.

General Motors sold over 20,000 Chevrolet Bolt EVs in the United States last year. Image source: General Motors.

The Bolt's sales have now risen for nine months in a row

Here's a look at how the Bolt's U.S. sales have fared since its introduction in December 2016.

A bar chart showing the Bolt's monthly U.S. sales rising steadily from early 2017.

Data source: General Motors' U.S. sales reports. Chart shows U.S. sales of the Chevrolet Bolt EV by month since its introduction in December 2016.

Bolt sales have increased steadily since early in 2017, getting a boost after GM finally made the little electric car available nationwide in August. Clearly, there's demand for the Bolt, though recently, GM has been offering some discounts to help encourage more buyers to try an electric vehicle. 

Right now, GM's incentives on the Bolt include generous leasing terms for those who finance through GM, and just over $2,000 in discounts and 3.9% financing for those who chose to buy instead of lease. Those are in addition to the federal and state tax credits available to buyers of new electric vehicles, which can exceed $10,000 in a few areas. 

All of that is helping Bolt sales, of course. But the main reason that the Bolt has sold well is simple: It's a nicely executed, well-regarded product.

How the Bolt's sales stack up against the Teslas 

As I noted above, the Bolt didn't do so well against the heavyweights from Tesla in December. The Bolt had recently pulled off some cheeky victories against its Silicon Valley rival, outselling all Tesla models in October and November.

But Tesla has a history of ramping up its deliveries in the last few weeks of each quarter, and it did that again in December. The upshot? The Bolt got beat by both the Model X and Model S last month, according to U.S. sales estimates from InsideEVs. But the Bolt still came in second in U.S. sales for the full year, beating the Model X -- and it far outpaced the Nissan (NSANY 0.54%) Leaf for both the month and the full year. 

Vehicle Dec. 2017 U.S. Sales Full-Year 2017 U.S. Sales
Tesla Model S 4,975 27,060
Chevrolet Bolt EV 3,227 23,297
Tesla Model X 3,300 21,315
Nissan Leaf 102 11,230
Tesla Model 3 1,060 1,772

Data source: General Motors, Nissan, InsideEVs. All numbers are U.S. sales only. Figures for Tesla are InsideEVs' estimates. 

The Bolt's days of challenging Tesla are probably numbered

The Bolt might well continue to keep pace with sales of the big Teslas, the Model X and Model S. But while Tesla has struggled to ramp up production of its more affordable Model 3 sedan, it's likely that it'll have plenty of Model 3s rolling out of its California factory before long. 

Tesla said recently that it's hoping to get up to a production pace of 5,000 Model 3s a week by the end of the second quarter. It's unlikely that GM's current production line for the Bolt could come close to keeping up, even if buyers suddenly materialized.

Long story short: Tesla's monthly U.S. sales should blow past the Bolt's before long. But the Bolt has done well to keep pace so far -- and I suspect that it's already selling at the pace GM hoped to see at the beginning of the Bolt's development. Tesla fans may not agree, but I say that counts as a victory for General Motors.