The 2016 Toyota RAV4 Hybrid is the sole mass-market crossover SUV that offers a hybrid powertrain and all-wheel drive.

That was a market pioneered by the Ford Escape Hybrid, in 2004, and one that Ford walked away from for 2013.

It turns out that there seems to be a market for compact crossovers with both AWD and high fuel economy.

DON'T MISS: 2016 Toyota RAV4 Hybrid: Gas Mileage Review

Toyota unveiled the RAV4 Hybrid last year, but the first copies weren't delivered until November.

The pace of sales has escalated sharply since then. Last month, the company delivered a whopping 4,185 hybrid RAV4s—out of a total of 32,261 RAV4s sold.

Meanwhile, sales of the company's high-efficiency Prius lineup have struggled, despite the launch of an all-new and much improved fourth-generation Prius Liftback for 2016.

2016 Toyota Prius, Catskill Mountains, NY, Dec 2015

2016 Toyota Prius, Catskill Mountains, NY, Dec 2015

Right now, gasoline is cheap and SUVs of all sizes are hot.

That hurts sales of hybrids, which track closely to gas prices. Moreover, no hybrid Prius (or any Ford) offers both an SUV form factor and all-wheel drive.

Enter the RAV4 Hybrid, of which more than 15,000 have been sold in six months. Over the same period, the Prius V wagon (now in its fifth model year) sold just 9,868.

ALSO SEE: Toyota Prius Family May Shrink As Low Gas Prices Dim Allure

In fact, May's RAV4 Hybrid sales exceeded every month's figure for the Prius V except March 2012, its sixth month on the market.

And RAV4 Hybrid sales have grown steadily since November, from just 54 that month to 4,185 in May, whereas Prius V sales have stayed below 1,350 every month this year.

That tends to lend some credence to the notion that the RAV4 Hybrid will supplant the Prius V wagon in Toyota's lineup at some point in the future.

2016 Toyota Prius V

2016 Toyota Prius V

Granted, at 33 mpg combined (34 mpg city, 31 mpg highway), the hybrid RAV4 delivers fuel economy more than 20 percent lower than the Prius wagon's 42 mpg combined (44 city, 40 highway).

But it's still the most fuel-efficient small crossover on the market, and that may be enough. Did we mention gas is cheap and crossover SUVs are hot?

More interesting is what this may say about Ford's decision to dispense with the sturdy, durable, and much-loved Escape Hybrid when it switched to a new generation of that crossover for 2013.

CHECK OUT: 2016 Toyota Prius: First Drive Of 56-MPG Hybrid (Nov 2015)

We'd heard rumors that Ford might add a hybrid model back to the Escape lineup for its mid-life update this year.

But the 2017 model came with no signs of a new, second-generation Escape Hybrid.

Meanwhile, sales of the Ford C-Max Hybrid, the tall five-door hatchback (sans AWD) that arrived for 2013 have lagged in recent years—not helped by two separate reductions in that car's EPA fuel-efficiency rating to reflect real-world results achieved by actual owners.

2015 Ford C-Max Hybrid

2015 Ford C-Max Hybrid

Ford will likely increase its production of hybrid vehicles when it launches the "Model E" hatchback in 2019, a vehicle built on next-generation compact underpinnings used for the Focus.

That vehicle is expected to offer the choice of hybrid, battery-electric, or plug-in hybrid powertrains.

Whether there will be a future all-wheel-drive Ford hybrid model launched any time in the next few years remains unknown.

READ THIS: 2017 Ford Escape quick drive review

Meanwhile, given the success of the new RAV4 Hybrid, we'd suggest that if you prefer a Toyota Prius V wagon instead, you may not want to wait too long.

The incentives are probably pretty good on that car these days—as they may be for the entire Prius lineup.

In other words, it's a good time to buy a hybrid vehicle. Especially a Prius wagon.

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