Toyota has upped its fuel-efficiency projection for its Plug-in Hybrid Vehicle (PHV), according to Bloomberg, which reports the automaker expects to top the Volt in its U.S. Environmental Protection Agency fuel economy rating.

Toyota’s U.S. Group Vice President Bob Carter, said the Plug-In Prius (AKA PIP) should manage 50 mpg in hybrid mode for combined city/ highway mileage, and earn 95 MPGe assuming its 4.4-kwh lithium-ion battery is recharged frequently.

“It’s still an estimate, but we are confident it’s going to be 95,” Carter said of Toyota’s projection Tuesday. The EPA rating will be known “in a couple weeks,” he said.

In comparison, the extended-range electric Chevrolet Volt can go more than 25-50 miles on a charge or so, is rated at 37 mpg combined, and 94 MPGe when relying mostly on battery power.

Toyota’s news represents an increase from a September estimate of 49/87. Satoshi Ogiso, chief engineer for Toyota’s Prius models, said the higher estimate follows further battery pack testing and additional newly developed “control programs.”

But before Prius fans get too excited, GM Spokesman Rob Peterson said driving conditions further separate the PIP from the Volt.

“The big difference here is in real-world conditions,” Peterson told Bloomberg. “The Volt’s ability to go all-electric at all speeds for 25 to 50 miles allows most drivers to commute on electricity only.”

The PIP has an electric-only mode top speed of 62 mph compared to the Volt’s top all-electric speed of 100 mph.

“At any point in time that a Prius driver exceeds 62 mph, their gas engine goes on,” Peterson said.

What’s more on average Volt drivers are filling their gas tanks but once a month, Peterson said.

For the PIP’s first year, Toyota aims to sell 15,000, compared to 45,000 year-two Volts.

But as you’ve also no doubt noticed, Toyota has a huge head start in gas-electric vehicles, and dominates in the hybrid market segment, occupying more than half of U.S. hybrid sales with its Prius line. The regular Prius, now called the third-generation “Liftback” has loomed large with over half of the limited hybrid car market.

Counting Prius v sales, the year-end total for the Prius line was 136,463 units sold compared to the next in line, Lexus (another Toyota brand) CT 200h, which sold 14,381 in 2011.

Toyota has chosen to lump all Prius sales numbers into one category, and it is projecting all four Prius models combined to account for 220,000 U.S. sales in 2012.

The company is now demoted to third overall in global sales, however, following disastrous effects from the March earthquake and tsunami.

GM has regained this spot, followed by Volkswagen, with Toyota following.