Last week, Toyota said it expects to sell 16,000 or more 2012 Prius Plug-In Hybrid models in the U.S. next year, once the car is launched (in June or before).

For all intents and purposes, it's a standard Toyota Prius hybrid with a larger battery pack that uses lithium-ion cells. The car can be plugged into a wall outlet to recharge the battery on grid electricity.

Still, we wonder whether the 2012 Toyota Prius Plug-In may be the car that gets U.S. car buyers more comfortable with plugging in their cars?

Toyota Prius Plug-In Hybrid prototype, tested in November 2010

Toyota Prius Plug-In Hybrid prototype, tested in November 2010

There's a huge amount of familiarity with the Prius brand--it's why Toyota is expanding it to encompass multiple models, including the 2012 Toyota Prius V wagon.

So it may be that consumers will be more comfortable with a Prius that plugs in more than they might be with the less familiar all-electric Nissan Leaf or Chevy Volt.

A volume of 16,000 Prius plug-ins over less than a full year equals the projected U.S. sales rate for Nissan Leafs next year, though it's lower than expected sales for the 2012 Volt.

$3K to $5K more than which Prius?

We think two factors will play a role in answering that question. The first one is price; Toyota has said the plug-in Prius will sell for $3,000 to $5,000 more than a standard Prius.

But the company hasn't said whether that amount is on top of the price of a base Prius Two model, which starts at $23,520, or a much higher-spec model like the Prius Five, at $28,790.

2012 Toyota Prius Plug-In Drive - March 2011

2012 Toyota Prius Plug-In Drive - March 2011

As the Union of Concerned Scientists has noted, hybrid makers usually add lots of features to their cars, making them comparable not to base models but to the highest trim levels of gasoline cars.

If Toyota bases the Prius Plug-In on its highest-spec model, that could price the car within a couple of thousand dollars of the 2012 Nissan Leaf, which starts at a base price of $35,200.

Toyota also will have to modify its claim that it would sell the least expensive plug-in car in the country; the 2012 Mitsubishi 'i' electric minicar costs $27,990, a level Toyota seems likely to surpass. They may have the cheapest "plug-in hybrid," however.

9 to 13 not-always-electric miles

The second factor is electric range. Toyota claims up to 13 miles of electric range, but it may not be continuous. The Prius Plug-In still switches on its gasoline engine to power the vehicle under high demand, even if it hasn't depleted the battery.

prototype 2012 Toyota Prius Plug-In Hybrid, April 2010

prototype 2012 Toyota Prius Plug-In Hybrid, April 2010

That's different from the 2011 Chevrolet Volt, a range-extended electric car, which runs only on electric power for 25 to 40 miles no matter how hard you thrash it.

After that, the Volt's range-extending gas engine switches on, but only to power a generator that sends electricity to the electric motor that actually moves the car.

Over a long weekend driving test in cold upstate New York last November, we only managed to get 9 or 10 indicated electric miles. Like all electric car batteries, the Prius Plug-In's lithium-ion pack is sensitive to cold.

We wonder whether drivers will think it's worth plugging in the car for such a relatively low electric range.

EPA rating: 60 mpg?

A final factor will be EPA gas-mileage rating. When the battery pack is depleted, the 2012 Prius Plug-In reverts to behaving like a regular, 50-mpg Prius hybrid.

Toyota Prius Plug-In Hybrid prototype, tested in November 2010

Toyota Prius Plug-In Hybrid prototype, tested in November 2010

The upcoming 2012 Prius V will be rated at 40 mpg; a standard 2011 Prius gets 50 mpg. Wouldn't it be tidy if the Prius Plug-In were rated at 60 mpg? We got 54 mpg on our test, but we had few around-town miles, so we didn't take advantage of electric running as much as many drivers will.

We've now driven prototypes of the 2012 Toyota Prius Plug-In Hybrid not once, not twice, but three separate times. For more background, read our drive reports here:

But what do you think? Is the Prius Plug-In the way to get U.S car buyers over the hump and comfortable with plugging in? Or has it already been passed by the Nissan Leaf and Chevy Volt, which provide much more electric range--albeit at a higher price?

Leave us your thoughts in the Comments below.

[Bloomberg via AutoblogGreen]

+++++++++++

Follow GreenCarReports on Facebook and Twitter.