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Electric driving in the 2012 Toyota Prius Plug-in

CNET gets a preview drive in the Toyota Prius Plug-in, the upcoming Prius that can be recharged from the grid.

Wayne Cunningham Managing Editor / Roadshow
Wayne Cunningham reviews cars and writes about automotive technology for CNET's Roadshow. Prior to the automotive beat, he covered spyware, Web building technologies, and computer hardware. He began covering technology and the Web in 1994 as an editor of The Net magazine.
Wayne Cunningham
5 min read
Toyota Prius Plug-in
Toyota has refined the Prius Plug-in, making it ready for its introduction as a 2012 model year production vehicle. Wayne Cunningham/CNET

Earlier this year, I spent a week driving a preproduction Prius Plug-in hybrid, but little did I realize that Toyota was using me and the other people who got to drive the car as guinea pigs, test subjects to help further refine the car for a 2012 production model. Toyota recently put me behind the wheel of a substantially tweaked Prius Plug-in, this one the result of everything learned from the earlier drive program. Still billed as preproduction, this latest Prius Plug-in boasted enhancements over the previous car, along with a full-blown marketing strategy.

In typical Toyota fashion, this new preproduction car was not radically different than the one I drove previously. And I confess to a lack of enthusiasm over this new driving opportunity. Despite that you can plug it in, it is still just a Prius.

2012 Toyota Prius Plug-in preview (photos)

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But that expectation crumbled a bit after seeing some of the improvements made to the car. And, like the previous version, it was a novel experience to drive a Prius at speed with the engine off.

During an initial presentation about the car, Toyota Vice President Bob Carter made it clear that the Prius brand would be a tent pole for the company. He talked up the four different models that will bear the Prius name: the original Prius liftback, Prius V, Prius C, and Prius Plug-in. A fan of the quick and maneuverable, I'm most looking forward to the Prius C, which will hopefully retain the sporty nature of its concept.

The presentation covered pricing for the car, which seemed high at $32,000, or $39,525 for a high-trim, fully loaded model. But that price is also subject to a $2,500 federal tax credit, bringing the base car under $30,000. Another journalist at the presentation suggested Toyota tailored the size of the Prius Plug-in's battery pack, at 4.4 kilowatt-hours, to make the car qualify for the tax credit, which is based on battery capacity.

However, the earlier version of the Prius Plug-in I tested had a larger lithium ion battery, at 5.2 kilowatt-hours. The refined battery pack is smaller than that of the previous version, yet it gives the car more pure electric range, 15 miles versus 13 miles. Not a huge change, but 15 miles is a rounder number. Taking the gasoline tank into account, total range remains at over 500 miles.

 
Toyota Prius Plug-in cargo area
Toyota reduced the size of the lithium-ion battery pack so as not to intrude on cargo space. Wayne Cunningham/CNET

Toyota also moved the charging port, as was shown by a model it had set up for photos showing the plug-in cable. Where it had previously been at the front fender, Toyota moved it to the right rear, the opposite side of the fuel tank filler. Nobody should have a problem pouring gasoline over the car's plug, as the hatch cover also has an embossed plug symbol. Similar to the previous test model, charging times are rated at 3 hours for a 110-volt outlet, and 1.5 hours at a 220-volt outlet. Toyota is also partnering with Leviton to offer buyers a level 2 charger, which should take mere minutes to fill the battery.

Once handed the keys to this new, refined Prius Plug-in, I was pleased to note that the cargo area had been restored. Where the previous version's battery pack caused a slight lift to the cargo load floor, the smaller battery pack in this preproduction model not only allowed a normal load floor level, but also an extra compartment for storing the charging cable.

The car started up, in Prius fashion, quietly. EV mode was already engaged and Toyota had charged the car up before this drive. But the range shown in the eyebrow display was only 11.8 miles, less than the promised 15. I wasn't thrown by the lower number, as trip computers always calculate the range based on how the car was recently driven. Fleet drivers are not always gentle on the accelerator.

This Prius Plug-in glided quietly forward under quarter acceleration, lacking even the sound generator Toyota implemented on the Prius V model. Out on the first stretch of the 4.5-mile driving loop, I stepped into it, and the gas engine promptly fired up despite the still glowing green EV mode icon on the instrument cluster. Letting off acceleration, the engine persisted, ruining the promised electric drive experience. Pushing the EV mode button repeatedly turned the EV mode icon off and on, but didn't shut off the engine.

 
Toyota Prius Plug-in
The instrument cluster shows the electric only range, which maxes out at 15 miles. Wayne Cunningham/CNET

Unlike the previous version of this car I had tested, EV mode was supposed to be selectable, something that Toyota touted over the Chevy Volt, which defaults to electric drive whenever possible. But the Prius Plug-in still has a mind of its own, kicking in the engine to respond to needed acceleration. That's understandable, although it would have been nice if the engine hadn't remained running even after I had stopped the car.

After the Prius Plug-in settled back into pure electric mode, a little testing showed that the engine would kick in at a little over half throttle. For the portion of the drive loop that entered the freeway, I found it possible to preserve electric momentum during the merge. But getting to the car's promised 62 mph without starting the engine was more difficult.

After running the drive loop twice, the electric range displayed by the car was only down to 8.2 miles, that figure due to both the occasional help of the engine and the trip computer recalculating based on my driving, which was only occasionally heavy-footed.

Toyota estimates that the Prius Plug-in will earn an EPA rating of 87 mpg equivalent, using the calculation for a plug-in hybrid vehicle. During my short drive there was no chance to verify that number, but it would be equally difficult to determine during a long-term test. Toyota says that, without charging the battery, the car would get 49 mpg. Individual performance will vary considerably depending on the length of trips and how frequently the car gets charged up. If you had a 10-mile commute and a place to plug in at the office, you might not use any gasoline all week. But a 60-mile commute and only occasional recharges would mean a figure much closer to 49 mpg, and suggest that you should have gotten the standard Prius liftback.

The Prius Plug-in will include a set of apps to help manage its plug-in architecture. These apps are an extension to the new Entune app system Toyota will offer in its vehicles. On an Android or iPhone, an owner will be able to set a charge time, prerun the air conditioning, look for public charging stations, and even use the car's GPS to find it in a parking lot.

Toyota will initially roll out the 2012 Prius Plug-in in the 14 West and East Coast states that follow California's vehicle emissions regulations, with wider sales to follow. Prospective buyers will be able to place their orders online beginning in October.