Just six years ago when the first major manufacturer plug-in electrified vehicles were experimentally launched, who knew that by now there’d be more plug-ins for sale in the U.S. than more-established regular hybrids?

What began with the extended range 2011 Chevy Volt and all-electric 2011 Nissan Leaf after Tesla’s 2008 Roadster blazed the path has led to 19 brands and counting proffering either plug-in hybrids or battery electrics or both.

At most recent count, excluding discontinued models winding down their finite stock, there are for sale in the U.S. 26 non-plug-in (regular) hybrids and 29 plug-in electrified vehicles (battery electric and plug-in hybrid).

Modern electrified cars in the U.S. date back to the 2000 Honda Insight and Toyota Prius hybrids. The 2000s saw hybrids proliferate as a means to save fuel and cut emissions, and new models are still being introduced and will continue to be.

Behind goals achieved by electrified powertrains are regulations that have in turn spurred automakers to go one step further with cars that can run either part time or full time on battery and motor power.

About Those Numbers

A look at the HybridCars.com sales Dashboard reveals 33 hybrid electric vehicles which sold units in January , but seven are discontinued and selling down existing supply, so we’re not counting these as current models.

Those discontinued hybrids, by the way, are in order of January sales: Honda CR-Z (89), Nissan Pathfinder Hybrid (73), Honda Civic Hybrid (16), Subaru XV Crosstrek Hybrid (13), Honda Insight (1), Buick Regal Hybrid (1), Mercedes E400H (1).

Actually, both hybrid vehicles and PEVs do see a rotating roster of models coming and going.

Among plug-in electrified vehicle (PEVs), there are 13 battery electrics, and 18 plug-in hybrids – if one counts the BMW i3 REx as a “plug-in hybrid” – adding to 31 PEVs. Within these vehicles, two – the Chevy Spark EV and Cadillac ELR – are discontinued, so we’re not counting them as current models.

That leaves the count at 27 hybrids to 29 plug-in cars, but this could be a measure of quantity over quality, if the key metric to measure them by is sales.

Despite there being almost equal numbers of models for sale between PEVs and hybrids, last year hybrids spoke for 1.99 percent of the 17.5-million passenger vehicle U.S. market, and PEVs amounted to 0.9 percent.

See CY2016 Numbers: December 2016 Dashboard

The tally of hybrid sales came to 347,029 units in 2016, and the market was down 9.7 percent from 2015. By contrast, plug-ins – factoring the combined strength of both BEVs and PHEVs – added to a record 157,181 sales, well above 2015’s 114,301 PEV sales (43,143 PHEVs and 71,158 BEVs).

What this means is despite not being eligible for subsidies, hybrids sell a little more than twice the volume. This can be attributed to a few factors, including hybrids are more established in consumers' minds, and their extra cost over conventional cars is less than it is for PEVs, they require no new behaviors (plugging in), and have zero range anxiety.

Plug-in hybrids share the benefits of no range anxiety due to gas back-up, but battery electrics do not, so they are tethered to the well-documented list of objections cited by those consumers who are passing them up at this point.

More Reasons For The Disparity

Plug-in electrified cars are also helped significantly by federal tax credits from $2,500-$7,500 per new car sale. State subsidies are variously available in some states too.

In California, cars like the Nissan Leaf, Chevy Bolt, Volt, Teslas, and others can qualify for $10,000 or more per car to offset their prices.

By contrast, hybrids stand on their own, as federal tax credits which were never nearly as much ended early this decade .

Notable also is California itself accounted for half of the U.S. PEV sales last year which speaks of a lopsided state of affairs. Many of the PEVs for sale are available only in California and markets that follow its zero emission rules.

Those are pejoratively called “compliance cars” because they are sold to comply with ZEV rules, and other markets, even if they want them, do not see them offered for sale.

On the flipside, hybrids are nationally distributed, and that also accounts for their superior sales numbers.

Winners and Losers

Among hybrids and PEVs there are a few models which do relatively well, and essentially carry two-thirds of the load for a slew of comparative sales laggards.

Does that sound harsh? It’s actually just honest, and some have wondered why some carmakers even bother to engineer and market certain cars that sell in negligible volumes, in cases fewer than 20 or even 10 units per month.

January was a down month for all types, but its numbers are telling.

On the hybrid list, eight current model cars sold fewer than 20 units in January, four sold between 20 and 100 units, 10 sold between 100 and 500 units, and only seven hybrids sold in excess on 1,000 units. Even without the “compliance car” factor weighing them down, hybrids mirror PEVs in terms of cars that do their share of sales, and those that do not.

Among PEVs, 12 sold fewer than 100 units last month, 11 sold between 100 and 500 units, and only five sold 1,000 or more units – though admittedly, January is an especially weak month for plug-ins. In December, where volumes were at a peak because people buy when they have the shortest wait to get the tax credit, there were seven vehicles selling over 1,000.

And this brings us to the cars that do the heavy lifting. We’ll look at an entire year, 2016, to give a clearer scope of how the leaders do.

Factoid: If the new Prius had been more successful this year , and sold 38,000 more units than it did (within realm of its best years), the hybrid market would have been only flat last year, instead of down by 10 percent.

Among hybrids, the top five by order of 2016 cumulative sales were: Toyota Prius Liftback (98,863), Toyota RAV4 Hybrid (45,070), Ford Fusion Hybrid (33,648), Toyota Camry Hybrid (22,227), Toyota Prius c (20,452).

Among PEVs by order of cumulative 2016 sales, the top sellers were: Tesla Model S (29,156), Chevy Volt (24,739), Tesla Model X (18,028), Ford Fusion Energi (15,938), Nissan Leaf (14,006).

As you can see, the Prius Liftback hybrid’s 98,863 units were not far behind the sum total of the entire top-five best selling plug-in cars, which amounted to 101,867.

The total of the top-five hybrids tallied to 220,260 out of 347,029 U.S. hybrid sales last year, or about 63 percent. The total of the top-five PEVs last year was, as mentioned, 101,867 out of 157,181, or about 65 percent.

Pretty close, isn’t it?

What Else Can Be Said?

Lots more could be said in slicing and dicing the data, but as a commentary on the numbers, it’s been reported gas prices are hurting sales, and that is only partly correct.

The market for electrified cars of all types is affected by many other factors including new/desirable models for sale spiking sales, old models on their way out hurting sales, and so much more.

Gas prices have otherwise more-significantly hurt hybrid sales which are down to 1.99 percent from a peak 3.19 percent in 2013, but plug-in sales were up to a record 0.9 percent in 2016.

Actually, some of this may just represent a shift among an approximate 4 percent of the U.S. market that buys either hybrids, plug-in hybrids, or battery electrics.

So, while hybrid sales have been dwindling, plug-ins have been on the rise. Does this represent hybrid drivers jumping ship and going to a plug-in? While plug-ins have captured sales from all over, in cases the answer is yes.

This adds a degree of nuance beyond the soundbite journalism saying the alternative energy market is down because gas prices are down.

A closer look at the “take rates” (market share) for entire calendar years is as follows:

2012 HEV take rate – 3.01 percent
2012 PEV take rate – 0.37 percent
Total: 3.38 Percent

2013 HEV take rate – 3.19 percent
2013 PEV take rate - 0.62 percent
Total: 3.81 Percent

2014 HEV take rate – 2.75 percent
2014 PEV take rate - 0.73 percent
Total: 3.48 Percent

2015 HEV take rate – 2.21 percent
2015 PEV take rate - 0.66 percent
Total: 2.87 Percent

2016 HEV take rate – 1.99 percent
2016 PEV take rate – 0.90 percent
Total: 2.89 Percent

Redesigned 2018 Camry Hybrid promises Prius-like efficiency.

Indeed, total electrified vehicle take rates have declined, but those for PEVs have risen progressively except for a relapse in 2015. This is not surprising, as it’s easier to move the percentage upwards when starting from almost nothing, but it also indicates the increased commitment by automakers.

What else does this mean? More insights could be drawn out, but it’s safe to say the market is growing, and more will be needed to push beyond a 4-percent market share ceiling that’s been in effect in the U.S.

This could happen with more electrified cars, although political realities could add a new twist to the plot – time will tell.

Otherwise, new models promised are expected to incrementally grow the market. New plug-ins that stand to sell in signifiant volume include the Chevy Bolt, pending Tesla Model 3, and 2018 Nissan Leaf. New hybrids include the Hyundai Ioniq, Kia Niro, new Camry Hybrid, and Nissan Rogue Hybrid, among others.

Automakers, as noted, are committing to more of everything globally. If things are not happening as fast as some would like, they are at least happening.