Folks looking to buy the most advanced hybrid car in the world will need to get their orders into dealers as demand for the new second-generation version of the Toyota Prius gas-electric hybrid is outstripping supplies.

In 1997 the Toyota Prius was the world's first mass-produced electric-gas hybrid vehicle. And it turned the automotive world on its ear with its easy driving nature and electronic wizardry.

But the new 2004 Prius is bigger and better in every metric of comparison. The all-new 2004 Prius ushers in a new era of electric-gas hybrid technology. The new Prius features increased interior space, moving it from a compact to the midsize class. Its new Hybrid Synergy Drive system supplies significantly more power and performance, best-in-class fuel economy, and best-in-market emissions performance.

The 2004 Prius is the first Toyota equipped with the new high-voltage/high-power Hybrid Synergy Drive powertrain. Like the original Toyota Hybrid System (THS) on the previous, uh, Prius, Hybrid Synergy Drive is defined as a "full hybrid system." Unlike competitive systems currently on the market, the full hybrid system is capable of operating in either gas or electric modes, as well as a mode in which both the gas engine and electric motor are in operation.

The advantages of a full hybrid system are numerous. The most important, however, is that because the car can be run under certain conditions with electric power only, fuel consumption, and emissions, can be reduced significantly.

A major difference between the new Hybrid Synergy Drive concept, and how it is improved over the current THS system centers on the duration of electric-mode driving and the peak power delivered electrically. The Hybrid Synergy Drive has a 50 percent more powerful 50-kilowatt drive-motor operating at up to 500 volts. This increased voltage and power is enabled by a newly adopted high-voltage power converter. Additionally, the generator in the new Prius has a higher peak operating speed that increases electric-mode operation in city and freeway slow-and-go operation. With 50 percent more electric power available and improved low-end torque from the drive motor, a significant boost in acceleration performance is possible.

Hybrid Synergy Drive increases fuel efficiency in the new Prius by 15 percent with combined mpg rising from the high 40's to the mid-50's. This enables Prius to have the best fuel efficiency rating of any midsize vehicle sold in America, delivering twice the combined mileage rating of its closest competitor. What's more, the midsize Prius also boasts a higher combined mileage rating than any compact sedan sold in America.

Hybrid Synergy Drive  significantly improves acceleration performance from the mid- 12-second range to the mid- 10-second range. This acceleration level is comparable to the Toyota Camry LE four-cylinder.

Also, Hybrid Synergy Drive enables Prius to be nearly 30 percent lower in emissions than the previous ultra-clean Prius, producing nearly 90 percent fewer tailpipe pollutants than a conventional internal combustion engine. Prius is be certified as a SULEV, or "Super-Ultra-Low-Emission-Vehicle" for tailpipe emissions in California and those states adopting California standards. In the rest of the country, Prius is certified as Tier 2, Bin 3. In addition, in California and those states adopting the California rules, Prius is certified as a PZEV category vehicle. PZEV, or "Partial Zero Emissions Vehicle" is a category composed of many elements. In addition to the SULEV exhaust standard, PZEV also requires meeting a zero fuel evaporative standard, a 150,000-mile durability demonstration and offering an extended emissions system warranty.

Prius features dramatic and distinctive aerodynamic styling. With a triangular mono-form shape, it is a dramatic visual departure from the original Prius, and contributes greatly to one of the most aerodynamic production vehicles on the planet. At an amazing 0.26, its coefficient of drag is a major factor in the vehicle's interior noise isolation and its significantly increased fuel efficiency.

The new bolder design is the wrapping for a much larger package that is full of surprises. The new Prius rides on an entirely new platform. Although its wheelbase is nearly six inches longer than the previous model it retains a relatively short overall length, casting a shadow only slightly larger than the earlier model. What is not so obvious from the outside is its significantly larger midsize interior.

Designers were able to achieve this tour de force in packaging by configuring Prius as a four-door lift-back. Not only does this layout work well with the vehicle's slipstream styling, its rear lift-back and fold-down rear seat combine to offer a new level of cargo hauling flexibility.

The new Prius is electronically controlled with by-wire throttle and shift control. The new by-wire shift control allows Prius to replace the traditional gearshift lever mounted on the floor or the steering column with tap-of-the-finger shifting of a small joystick mounted on the dash.

A Smart Entry and Smart Start option allows keyless entry and keyless startup. As the driver reaches for the door handle, an on-board sensor will recognize the signal from a key in his pocket and automatically unlock the doors. Since the driver has already been security-cleared to enter the vehicle, he can leave the fob in his pocket, push a start button located on the dash, and drive away.

Smart Entry and Start is one of only a handful of options offered in the new Prius. Offered in a single, well-equipped trim level, Prius standard equipment includes ABS brakes, power windows, door locks and mirrors, and a unique electric inverter air conditioning system. Instead of running off the fan belt, the new inverter air conditioner is fully electrically operated. Not only does this improve fuel efficiency, it ensures passenger comfort, even when the gasoline engine is off and the car is being propelled only by the electric motor.

Toyota has learned a lot about Prius since its launch in America two-and-a-half years ago, with its larger interior space, increased power and performance, best-in-class fuel economy, and best-in-market performance, Toyota is convinced that the new Prius will continue to lead electric-gas hybrid technology into the mainstream market.

Apparently many others agree. Most dealer says to get one, you need to order and the current backlog is running 3 to 5 months before delivery.