The Toyota Prius hybrid was once the poster child for green technology, even a status symbol for environmentally-conscious celebrities.

Over three generations, the Prius was largely responsible for cementing Toyota's status as the number-one seller of green cars.

But lately the Prius seems to have lost a bit of its luster.

DON'T MISS: 2016 Toyota Prius: Gas Mileage Review Of 50-MPG-Plus Hybrid (Dec 2015)

Despite the introduction of a completely-redesigned, fourth-generation version for the 2016 model year, Prius sales have been sluggish over the past few months.

Between January—when the fourth-generation model was introduced—and June, Prius deliveries dropped 10.5 percent from the same period in 2015.

That's better than the 15.5-percent decline in overall hybrid deliveries, but unprecedented for the launch of a redesigned Prius, according to WardsAuto.

2016 Toyota Prius Four Touring

2016 Toyota Prius Four Touring

Wards attributes this to several factors, including low gas prices, the 2016 Prius' somewhat controversial styling, and increased competition from plug-in hybrids.

Cheap gas is proven to dampen sales of all green cars, and the Prius isn't the only model to be criticized for its styling.

But could it be that plug-in hybrids—not to mention battery-electric cars—have made the Prius passe?

ALSO SEE: Toyota at 9 million hybrids, now makes more than 1 million a year

With a plethora hybrid, plug-in hybrid, and battery-electric models now on sale, it's fair to say that the Prius isn't as novel as it once was.

The Mirai hydrogen fuel-cell car is now arguably Toyota's technology flagship, even though its sales are minuscule.

Today's plug-in hybrids in particular offer the same convenience of the Prius, but with greater overall efficiency thanks to substantial electric-only driving ranges.

2016 Toyota Prius Four Touring

2016 Toyota Prius Four Touring

Yet it would be a mistake to say that these developments have rendered the Prius irrelevant.

Toyota still sells close to 200,000 of the cars per year, momentum which recently pushed it past the milestone of 9 million hybrids built worldwide.

Controversial styling aside, the fourth-generation model is also a genuine improvement over the car it replaced.

MORE: 2017 Toyota Prius Prime: first drive of new plug-in hybrid

It's the most fuel-efficient car without a plug currently on sale in the U.S., achieving an EPA-rated 56 mpg combined in Prius Two Eco trim, and 52 mpg combined in other configurations.

The new version is also much nicer to drive than the previous three generations, the result of Toyota's decision to emphasize roadholding and handling for the first time.

In addition, Toyota has the plug-in hybrid angle covered as well.

2017 Toyota Prius Prime

2017 Toyota Prius Prime

Set to go on sale in the U.S. later this year, the 2017 Prius Prime boasts an 8.8-kilowatt-hour lithium-ion battery pack, enough for an estimated 22 miles of electric-only range.

Unlike many other makers' plug-in hybrids, the Prius Prime will also be available in all 50 states.

So even if consumers are no longer wowed by the standard Prius, Toyota can always woo them with the Prime.

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