As the world gears up for the crusade against climate change, a new breed of car tuners and tinkerers is emerging. Their goal is not speed, but endurance. The new-age definition of high performance is not how fast, but how far.

Forget about turbochargers or nitrous injection or gasoline itself. To these green hot-rodders, even Hybrid Electric Vehicles are already so last-century. What the world needs now, they say, is Plug-In Hybrid Electric Vehicles. And if the major automakers aren't yet ready to build PHEVs, a growing number of small companies and tech-savvy individuals are showing them the way.

The concept is simple: take an existing HEV such as a Toyota Prius or Ford Escape Hybrid, and equip it with an additional and/or more powerful battery.

Unlike the hybrids' original batteries, which are recharged by the gasoline engine or by recapturing energy under braking, the PHEV's batteries are designed to be recharged by plugging them into the electric power grid, typically while the vehicle is parked overnight.

And while the stock hybrids can run on battery power alone for only brief spells at very low speeds, the PHEV's batteries contain enough juice to propel the vehicle in electric mode for meaningful distances at real-world urban speeds (up to 55 km/h).

A PHEV with an all-electric range of 40-60 km would enable most North Americans to do their daily driving with little or no contribution from the gasoline engine (A fact, even sizable automakers like GM are just catching on to with its Chevy Volt concept from the Detroit show). When the PHEV battery is exhausted by greater distances or higher speeds, the car simply reverts to normal hybrid operation (but at that point, fuel economy is diminished somewhat by the added weight of the PHEV battery).

Fifty kilometres is the all-electric range claimed for the Toyota Prius PHEV created by Concord, Ontario-based Hymotion. The small Canadian company is a leader in the PHEV conversion industry. To date it has focused on fleet customers, but sales to individuals are in the pipeline.

In half a day or less, Hymotion can install its plug-and-play PHEV module under the trunk floor of your Prius. The self-contained 73-kg unit incorporates a 5-kWh lithium-ion battery pack, smart charger, power electronics and various safety-related interlocks and cut-offs. The original Toyota Hybrid system is left untouched, but note that the conversion would still void the factory warranty.

According to the company, recharging takes 5.5 hours at 120 volts or four hours at 240.

By recharging overnight, when demand for hydro from other sources is low, PHEVs would tap into excess generating capacity. That would create efficiencies for the utilities that could even lead to lower electricity prices, say PHEV proponents.

Some American sources say there's enough spare capacity in that nation's electricity generating system to recharge the equivalent of 84 percent of the current U.S. fleet of cars and light trucks.

For Americans, much of the push for PHEVs is framed in terms of energy security and the trade balance, since the plug-ins would enable "home-grown" electricity to displace imported oil.

But what about the environment? Aren't emissions simply being shifted from automobile tailpipes to power-station smoke stacks?

In terms of noxious emissions and human health, that isn't necessarily a bad thing, since smoke stacks tend to be located away from cities, while tailpipes are where most of the people are. Arguably, too, it's easier to control pollutants from a single power station than from thousands of individual automobiles.

As for carbon dioxide -- the global-warming villain -- it all depends. Electricity generated by renewable sources (solar, wind or hydroelectric) generates no CO2 . The same is largely true of nuclear, though of course the atomic option has other issues of its own...

For electricity generated from fossil fuels, estimates vary widely, but the consensus seems to be that the full-cycle "carbon footprint" of electricity is lower than gasoline's. "The entire process of moving a car one mile is more efficient using electricity than producing gasoline and burning it in a car's engine," said a U.S. department of energy report.

In plain old dollars and cents, too, a PHEV's cost per kilometre on electricity is much lower than on gasoline.

Fine, but what's the price for the PHEV itself? Calcars, a U.S.-based group that promotes PHEVs, estimates that with mass production, automakers could sell small vehicles with a 50-km battery range for $3,000 US more than a conventional hybrid, and $5,000 more than a standard gasoline vehicles.

Meanwhile, Hymotion is projecting an installed price of about $11,000 to PHEV a Prius. Whether the conversion would ever pay for itself is highly debatable -- but it's also not the point.

If a car buff spends $11,000 restoring an antique car or go-fast tuning a 10-year-old Civic, nobody demands that the investment has to pay for itself. The payback is in the satisfaction received from the end result.

Out there on the leading edge of our new-age go-farther movement, the same principle applies.