100 mpg on a single "tank"?
By Eric Peters
for immediate release

The 100 mpg carburetor was just an urban legend -- but the 100 mpg hybrid is very real indeed.

It's just not quite ready for prime time yet.

Afterrmarket companies like EDrive Systems of California (www.edrivesystems.com ) have been modifying factory-built hybrids like the Toyota Prius to be "plug-in capable" -- so that their onboard battery packs can be recharged by regular household current, just like a pure electric car.

Ordinarily, a hybrid's batteries are charged by the car's gasoline-burning engine as the car is driven. But that burns gas -- and thus limits the potential efficiency of the system. By adding a plug-in outlet, the hybrid can recharge its batteries without burning any fuel at all.

The result is an exponential increase in economy -- as much as 100 mpg on a single charge.

Plug-in hybrids can also operate exclusively on pure electric power for longer periods of time -- as much as 30 miles at speeds of 35-40 mph. (Most factory-built hybrids only use their batteries/electric motors to supplement the onboard gas-burning engine; or when the vehicle is stationary or operating at very low speeds.)

But unlike pure electric cars , which have been hobbled by their limited range and lengthy recharge times, the plug-in hybrid still has its gas engine for back-up when the batteries run low -- so it won't conk out on you after 50-70 miles of driving.

These vehicles have the range and every usability of a standard hybrid -- with double (or more) the mileage. EDrive says its modified Prius, for example, is capable of as much as 200 mpg. That would be a a three-fold improvement over the "best case" mileage potential of the standard Prius.

In addition to the substantial fuel savings, the plug-in hybrid's environmental impact is extremely low, too. Like a pure electric car, it produces zero emissions (unburned hydrocarbons and carbon dioxide, the principle "greenhouse" gas produced by internal combustion engines) when operating on battery power alone. And while some C02 is produced by the utility plants which create the electricity used to recharge these vehicles, the extremely low overall emissions output -- even when the gas engine is in use -- make plug-ins a very attractive trade-off relative to both conventional cars and conventional hybrids. (If power generation were exclusively hydro-electric or nuclear rather than coal-fired, total C02 emissions would be virtually nil.)

Unfortunately, the current cost of a plug-in conversion is still prohibitive -- on the order of $10,000-$12,000 per car -- and voids the car's factory warranty. These downsides mean plug-ins are not yet viable options for the average driver. It would take a decade or more of driving -- even at $3.00 per gallon -- to amortize the $10,000-$12,000 conversion costs.

However, these costs should come down considerably as production of plug-in hybrids "ramps up" from a handful of essentially hand-built prototypes per year to perhaps as many as tens of thousands mass-produced annually. And look for the automakers themselves to get in on the action -- offering plug-ins as factory-built, fully-warranted (and 100 mpg capable) OPEC fighters within the next 2-3 years or so.