The Toyota Prius is a historic vehicle by any measure. It was the first hybrid to be mass-produced, and it remains the only one to achieve truly mass-market popularity – since it first went on sale in Japan in 1997, it has sold nearly six million units in over 90 worldwide markets.

Toyota introduced the Prius Plug-in Hybrid in 2012 and, by the much more modest metrics of the plug-in world, it sold relatively well. At the apex of its life cycle, it was the third best-selling plug-in vehicle in the US (after the Volt and the LEAF). By the time production ended in 2015, it had earned the distinction of third best-selling PHEV worldwide (after the Volt/Ampera and the Mitsubishi Outlander PHEV). As of April 2016, worldwide sales totaled 75,400.

At the beginning of this year, the fourth-generation Prius went on sale, featuring not only a much sportier appearance, but also significant advances in battery, electric motor and gas engine technologies. Toyota followed this up with a next-generation plug-in Prius, the Prius Prime, which should be arriving at US dealerships as you read this. The new plug-in has a 25-mile EPA-estimated electric range and will be available in all 50 states.

A hybrid breed apart

Toyota is branding the Prius Prime as a breed somewhat apart from the Prius family. The previous-generation plug-in looked just the same as the plain Prius, but this time around, “we made efforts to be sure Prius Prime stood out,” Nathan Kokes, Prius Prime Marketing Manager, told Charged. “If you put the cars side by side, you see that the front, from the A pillar forward, and the rear, from the C pillar back, are completely different. The hood is designed differently, the air intakes in the front of the vehicle, the grill, the headlights, are all very eye-catching.”

In fact the quad-LED headlamps aren’t just designed to look cool, but also incorporate some new smart features. “They can stay in high-beam longer because they have a blocking system that measures [the distance and position of an oncoming vehicle] and just blocks out the high beams for that one section, and then the section around them will still have the high-beam light on,” Kokes explains.

The rear of the vehicle features an LED tail lamp that wraps completely around the tailgate. “The rear glass is eye-catching because it has what’s called a dual wave design, so it kind of swoops down in the middle,” said Kokes. “That is reflected on the glass and also on the rear spoiler itself. And that rear tailgate is made of carbon fiber, so it’s got a great feel. When you lift it, it feels very light. It’s strong, and it’s made of advanced materials that early adopters are really interested in.”

Plug-in puzzlement

Here at Charged, we have often bemoaned the fact that consumers and mainstream media outlets still don’t understand the differences among the various types of electrified vehicles. Toyota wants to reduce that confusion, and that’s part of the reason for the Prime’s distinctive styling.

“Being immersed in the alt-fuel category, we are all very well versed in what PHEV means, but for the general market, from our research, we’ve found a lot of confusion,” said Kokes. “People barely know what hybrid means outside of a couple of metropolitan areas, and even a lot of hybrid buyers don’t know what they have. So when you start throwing in additional terms like plug-in hybrid…”

“We wanted to try to reduce the complexity and name this car as the top-level Prius,” said Kokes. “It is the most efficient Prius. We’re going to try to show people that this vehicle is within the Prius family, because people know and trust Prius, but it’s differentiated with a name, and they’ll try to find out more about what that means and if it’s right for their lifestyle. We anticipate that when people learn about it, and it’s explained on the dealership lot or on our very detailed web site, it will give people an explanation of what the benefits are of owning it and how it works.”

Ask the person who owns one

Toyota designed the Prius Prime with the benefit of a lot of input from the previous generation of Prius Plug-In owners.

“The biggest influencers we have are our owners,” said Kokes. “We do extensive questioning and surveying and focus groups with our owners. We do regular owner panel surveys just to get a sense of what’s working, what’s not, and what the requests are. We are crunching data all the time and making recommendations based upon our owner feedback, what competitive moves are happening, and what the advancement of the technology seems to be in the marketplace. We try to really keep our fingers on the pulse of what consumers are looking for.”

One thing that customers wanted was “stand-out styling,” Kokes told us. “The consumers that are buying these vehicles display a lot of early adopter traits. So they’re looking for a vehicle that reflects their choices. They’re likely going to be some of the first people to buy new electronics, the newest phones, because they want to be seen as thought leaders.”

Powertrain progress

“For the powertrain, we wanted to push electric driving as much as we could without sacrificing overall efficiency and hybrid efficiency of the vehicle itself,” said Kokes. “Because we know this consumer is interested in exploring what EV driving is all about, but might not want to take that full step into a pure EV and potentially sacrifice some lifestyle aspect. So it was a big exercise in balance [to find] the right size of the electric powertrain compared to the hybrid powertrain.”

The Prius Prime is built on Toyota’s New Global Architecture platform. Its drivetrain shares a lot of components with that of the hybrid model, but there are a few important differences. “The engine and the motors are the same, and the transaxle is the same,” Kokes tells us. “What’s different is the addition of a one-way clutch in the transaxle of the Prius Prime, which allows the second motor to also act as a traction motor for the vehicle, so you get the benefit of a dual-motor system.”

Like the standard Prius, the Prime has two electric motors, called Motor-Generators 1 and 2. Previously, MG1 was used only to start the gas engine and to handle regenerative braking. However, the Prime has a Sprag one-way clutch that locks in with the crankshaft during EV Mode, so that both MG1 and MG2 can be used as traction motors.

“With Prius Prime, both motors are used to drive the vehicle forward, so you get the improved EV driving capability that the customers are looking for, and it can go all the way up to 84 mph – full highway speed driving in all-electric mode,” Kokes explains. “So you get great EV drive feel when you’re accelerating as well as sustained EV driving in freeway situations.”

Why plug in?

The popularity of the previous Prius Plug-in was always something of a puzzle to EV pundits. Unlike the Volt, its electric range (11 miles by EPA standards) is not long enough to allow most trips to be made on electricity alone, so when you do the math, the gas savings along are unlikely to justify the higher purchase price.

For Californians, eligibility for the coveted “green sticker,” which gives access to HOV lanes, is surely a powerful inducement. In fact, many countries and regions offer monetary and other incentives for plug-in vehicles, but few offer them for conventional hybrids, so for many motorists, it makes sense to opt for the plug-in model, even if you never plan to plug it in. And it’s only natural that first-time plug-in buyers are likely to opt for a trusted model such as the Prius.

Bigger battery, more miles

Whatever your motivation for buying a plug-in may be, more electric range is always better, so Toyota listened to owners who complained about the minimal range of the previous Prius Plug-In, and doubled the battery capacity. The Prius Prime has an 8.8 kWh battery, and electric range is now an EPA-estimated 25 miles. Thanks to improvements to the battery technology and packaging, the new pack is only about 80% larger and 60% heavier than the old one.

Inevitably, the increased range comes with a trade-off, and as always seems to be the case with plug-in vehicles, that trade-off is cargo space – Toyota had to raise the cargo floor height by a couple of inches to accommodate the Prime’s bigger battery. Whereas the previous Prius Plug-in had the same cargo space as the ordinary hybrid (21.6 cubic feet with the seats up), the Prius Prime has substantially less than its plugless sibling (19.8 cubic feet instead of 24.6). Musicians and campers can console themselves with the fact that that’s still more than the Volt can offer.

Unlike the standard Prius, the Prime has two individual seats in the rear, instead of a bench seat that can seat three in a pinch. All in all, a certain amount of interior space has been sacrificed to give us a more usable electric range. Whether the trade-off is worth it is a question each individual driver must answer, based on how they plan to use the vehicle.

Proud to be electric

Another complaint about the old Plug-In was that there was no way to lock it into pure electric mode – the legacy engine would kick in whenever you pushed the pedal past a certain point. And the gas engine isn’t always ready for action – every Prius driver has had the disconcerting experience of flooring the accelerator and having to wait half a second for the car to actually accelerate.

That’s all over now – the Prius Prime features three driving modes. When freshly charged, or any time that sufficient battery charge remains, it defaults to EV Mode, in which it acts like a pure EV, all the way up to a top speed of 84 mph. Once the charge is depleted, the Prime switches to Hybrid Mode, in which it drives like an ordinary Prius. EV Auto mode allows you to maintain your existing charge as long as possible, so you can save it for later, perhaps to glide silently through a sleeping suburb.

Saving gas and electrons

The 8.8 kWh battery can be charged relatively quickly from a 110-volt household outlet, using the cable that comes with the vehicle. “Just plug it into the standard outlet in the garage, and a little over five hours later you have a fully charged battery,” Nathan Kokes told us. “So there’s no special equipment to buy, and no added expense or complexity for the buyer. Unless you are an ER doctor who sleeps 4 hours a night, you will have a charged battery when you get up in the morning.”

“We found with the previous generation that it’s better to let the consumer buy a Level 2 charger on their own,” said Kokes. “There are so many choices out there that they can just go to Amazon and pick one up. A Level 2 charger takes the charging time down from 5 hours to 2 hours, so the difference for the additional cost is a big question mark for us. We really see the benefit of Level 2 charging for workplace or public charging, but when you’re home, generally speaking, you’re going to plug the thing in overnight.”

Toyota is especially proud of the Prime’s fuel efficiency, which Kokes told us is the highest of any vehicle sold in the US: 133 MPGe. The total range is also the highest in the industry: 640 miles with a full tank of gas and a full battery.

“The engineers worked tirelessly to make sure that the system itself would be the most efficient it could possibly be. They were able to achieve the top efficiency of any vehicle – it even beats pure electric vehicles in terms of the total efficiency of the system. It’s the most efficient car in America.”

That achievement is thanks to the longevity of the company’s electrification program. “Toyota has done so much to push and promote and get people comfortable with vehicle electrification, and that was just one of the benefits of our R&D efforts, for the engineers to eke out a little bit more efficiency.”

The price of a Prime

The price premium for the Prius Prime is not prodigious. Starting MSRP is $27,100, compared to $24,685 for the 2017 Prius. A federal tax credit of $4,500 is available, and California residents in the right income bracket can claim an additional $1,500 rebate (and of course the prized green sticker). So for many buyers, the pinnacle of technology that is the Prime could actually end up being cheaper than a plugless Prius, with the gas savings as a free bonus. That’s a can’t-lose proposition that begs the question: Why buy a car without a plug?

In fact, Toyota may already be thinking along those lines. In September, Prius Prime Assistant Chief Engineer Shoichi Kaneko told AutoblogGreen that someday all Prii may come with a plug. “Ultimately, PHEV may be the way to go,” Kaneko said.

This article originally appeared in Charged Issue 28 – November/December 2016. – Subscribe now.