Was Tesla Model S January's best-selling plug-in?

And America's best selling plug-in vehicle for 2013 is...the Tesla Model S? That's what Inside EVs calculates by way of extrapolating the company's production capacity of 400 units a week and the fact that the company's still working down its backlog of orders.

Tesla, of course, is mum on its sales numbers, with spokeswoman Shanna Hendriks saying only that the company will reveal some sales details during its fourth-quarter 2012 earnings call scheduled for later this month.

So, that leaves us with speculation. With as many as 1,600 Model S sedans being delivered a month, Tesla in January may well have led all automakers, as General Motors and Nissan were hamstrung by inventory issues for the Chevrolet Volt extended-range plug-in and Leaf EV, respectively. Leaf sales in January fell 3.8 percent from a year earlier to 650 units, while the Volt moved 1,140 units, which was twice as high as 2012 figures but down from 2,633 units in December. Meanwhile, the Ford C-Max Energi plug-in hybrid moved 338 units in January, while Toyota sold 874 of its Prius Plug-in Hybrids. So, if Tesla did deliver 1,600 Model S vehicles in January, well, that'd be quite something.