What is it?
The standard Toyota Prius has proved immensely popular with the public, celebrities and company car drivers alike. Whether it's the low running costs or the thought that you're saving the planet, there's no denying that the Japanese company came up with a winning formula in the Prius.
Now Toyota has gone one step further and developed a plug-in version. It's still a conventional hybrid, with a 1.8-litre petrol engine in the front and a battery pack in the back, but it's now possible to charge the battery from an electric car charging point. That means that the latest Prius can cover 12.5 miles using electric power alone - as opposed to the mere 1.2 miles of the current model.
That doesn't sound like a huge amount, but according to Toyota it's enough to cover the majority of daily commutes, particularly in central London. It also means that the Prius PHV (Plug-in Hybrid Vehicle) will return an incredible 108.6mpg and emit only 59g/km of CO2, so it's super clean and unbelievably cheap to run.
From July, 20 Prius PHVs will take to the streets of London, but they will be run by a select few - namely employees at Sky and News International, two of Toyota's big company car customers, along with staff at Transport for London, the Metropolitan Police and the Government Car and Despatch Agency. You won't be able to buy one until early 2012.
Is it any good?
The PHV is virtually identical to the standard Prius inside and out. The only exterior difference is a small rectangular cap located just above the front passenger side wheel arch. That's where you plug in the charger for the battery.
The only notable change inside is a slightly higher boot floor due to the bigger battery, but it's difficult to notice and barely eats into the boot space. The plug-in model is also 130kg heavier than the existing Prius.
With the petrol engine and the electric motor working together the Prius pumps out 134bhp and it will hit 62mph in 13.7 seconds with a top speed of 112mph. As with the looks, it's pretty much identical to the standard Prius behind the wheel.
You'll struggle to get the petrol engine to kick in at town speeds though, as the car silently sails along using electric power only. The motor releases all its pulling power from zero revs, so the Prius is actually quite nippy around town and ideal for keeping up with the cut and thrust of city traffic.
It even tells you how eco-friendly you are by displaying an image of a growing forest on the screen in the dash to represent how little CO2 the car is emitting.
Should I call the bank manager?
There's no word on prices yet but bank on the fact that the PHV will cost significantly more than the standard car when it eventually goes on sale. Toyota says that the companies running the 20 cars due to arrive in July will pay £300-£400 per month to lease them, but that's not reflective of how much Joe Public will pay when it hits the showroom.
A neat new addition, unique to the Prius PHV, is the air conditioning system, which alters the temperature inside the car while the battery is charging up, so the car doesn't waste energy heating or cooling the interior on the move.
If Toyota can get the price right the Prius PHV could be a phenomenal success. Such low running costs are hugely appealing and the Prius is ideal for city dwellers with a short but congested commute. It makes far less sense for regular motorway drivers, but that's not who Toyota is gunning for. If the trials go well and the company can sell the car with a reasonable price tag, then it could well be as successful as the current Prius - if not more so.