The king of hybrid cars, the Toyota Prius, will not offer a third generation hybrid drive until sometime in 2009 as a 2010 model - at least that's based on the latest reports (and rumors). 

Early reports once indicated that the new hybrid drive would offer lithium-ion batteries. "We will change the battery from nickel hydride to the lithium battery," CEO Katsuaki Watanabe told Business Week last year. 

Not long after, however, rumors against such a lithium move hit the blogosphere. Later rumors even claimed that lithium-powered hybrids from Toyota had been delayed by at least 1 to 2 years due to safety precautions. All the while Toyota has been very tight-lipped on the subject.

Nonetheless, Toyota has confirmed that lithium will not power the 2010 Toyota Prius, at least not at first.

Toyota continues to work on its lithium technology. Toyota has even indicated that the first Toyota hybrid to utilize lithium might actually be a Lexus model, followed by a plug-in version of the Toyota Prius.

The standard 2010 Toyota Prius also will not be a plug-in hybrid. However, Toyota will begin selling a NiMH-powered plug-in Prius for fleet sales starting in late 2010. Sometime in 2010, the plug-in Prius might also become available for individual sales.

Bigger, faster, more efficient Prius, nonetheless, what will it cost?

Without lithium, major improvements are not expected in fuel economy. Still, the third generation Prius will be a little bigger, faster and 10 - 20 percent more fuel efficient than the second generation Prius. 

That could mean more than 50 mpg on the highway, and as high as 60 in the city - conservatively speaking - in a body 3 to 4 inches longer and an inch wider. Obviously, those whom have mastered the art of hybrid driving will achieve far better numbers.

So, how much faster? The new Prius will move from a 1.5-liter inline 4 to a 1.8 inline 4 engine that adds 25 extra horsepower for a total of 100 hp. Combined with a new, advanced electric motor that new Prius will offer as much as 160 hp compared to today's 110 hp.

Does that make the third generation Prius worth more than the current version? Will there be a price increase, a decrease?

Originally, Toyota had suggested that the next generation Toyota Prius, utilizing a Third Generation Hybrid Synergy Drive - a hybrid powertrain predicted to be half the weight of the current Prius powertrain - would cut in half hybrid technology costs.

Toyota sources claimed the third generation hybrid technology, "will cut prices for eco-friendly vehicles, reduce fuel costs and slash production expenses."

Was that prediction made utilizing lithium? Was the prediction battery independent?

How did, or does, this affect price? 

Likewise, Toyota will also have to contend with the Honda Insight for hybrid sales.

2010 Prius waiting lists?

Toyota is already planning a 60 percent increase in Prius production for 2009. This increase seems to coincide with the launch of the third generation Prius expected sometime in 2009, probably late Spring of 2009 - a few months after the third generation Prius debuts at the Detroit Auto Show.

Is a little bigger, faster and more fuel efficient Prius worth a 60 percent increase in production? Could third generation costs go down? Must they go down?

Consumers have been embracing the Prius in greater numbers, month-after-month. And if gas prices stay high, consumers appear ready to convert to hybrids in even larger numbers.

Is this enough to justify a 60 percent increase in Prius production - scheduled for 2009 as Toyota heads into the third generation launch?

It seems so, even without lithium.

Prius derivatives?

Still, what does all this mean? 

Will rumors of a non-plug-in, 100 mpg Prius prove to be unfounded?

It seems hard to imagine that the next generation Prius could achieve 100 mpg, without some sort of plug-in functionality - which is a possibility. Still, Toyota has steadily maintained that plug-ins are not yet feasible, especially without lithium batteries.

Then again, perhaps the 100 mpg Prius is a derivative Prius, such as a smaller, city Prius. 

Toyota has claimed that the future could hold multiple derivatives of the Prius, and a larger Prius - in addition to the smaller Prius. Both a smaller Prius and a larger Prius have made auto show appearances.

Might this smaller Prius also be sold as a Prius in 2009 as a 2010 model? Is there room, today, for both a full-sized, larger Prius and a smaller, city Prius?

At this point there are simply more questions than answers regarding the 2010 Toyota Prius. However, Toyota has indicated that it would debut a new unique hybrid at NAIAS in 2009, so the picture should clear greatly then.

If gas prices stay high, Toyota's third generation hybrid vehicles, especially the Prius, appear to have a bright future, regardless of when lithium finally starts powering next generation hybrid vehicles.

Thanks article from http://www.soultek.com/clean_energy/hybrid_cars/third_generation_toyota_prius_in_2008.htm

Here are the first questions to ask when thinking about the Chevy Tahoe Hybrid and GMC Yukon Hybrid: Do you need a vehicle that can haul up to eight people? And carry cargo? And tow up to 6,000 pounds? Because if you don’t really need the extra space and towing capacity, then you could buy a much smaller vehicle than the Tahoe and Yukon, and without any kind of advanced auto technology, you could burn a lot less fuel.

But if a full-size SUV with lots of load-hauling capability is a must for you—and you’re trying to reduce the amount of energy and gas money required for those heavy-duty jobs—then General Motors has come up with a hybrid with your name on it.

The two-wheel-drive versions of the Yukon and Tahoe hybrids are rated at 21 mpg in the city, and 22 mpg on the highway. That gives the gas-electric Yukon and Tahoe top ranking for fuel efficiency in the full-size SUV category. In fact, those figures match the city numbers for the four-cylinder Toyota Camry and beat the V-6 Camry in the city. All models come equipped with a 6.0L V8—for a combined output of 332 horsepower and 367 lb-ft of torque—and can tow up to 6,200 lbs.

Yeah, But How?

GM’s so-called “two-mode” hybrid technology is part of a strategy to develop hybrids that improve fuel economy at highway speeds as well as in the city, using two separate modes of operation. The electric motors deliver their power through variable-ratio gear sets, which allows them to be smaller and lighter while drawing less electricity.

The main distinction of the two-mode hybrid, though, is the use of a second set of gears configured specifically for moving big vehicles at highway speeds. The Honda and Toyota systems (and the Ford Escape Hybrid, which is similar to Toyota’s technology) use a single set of gears for both city and highway driving.

Larry Nitz, executive director for hybrid power train engineering at GM, explained, "It's two electronically controlled, continuously variable modes, and they have a point, a gear ratio, at which all the speeds synchronize. At that gear ratio, the engine switches from one mode to the other mode without a speed change." As a result, Mr. Nitz said, the transition between modes, at a speed that is equivalent to second gear in a conventional car, is nearly imperceptible.

"When you're in the economy or city mode, you lean on the electric motors more, because the electric side allows you to operate more efficiently at light loads," Tim Grewe, chief engineer for rear-drive hybrids at G.M., said. "When you are in performance or highway mode, you use more gears, because gears operate more efficiently for the high loads."

Each of the two-mode hybrid's two electric motors is about half the size of a motor used in today's hybrids. Even so, the two-mode system is powerful enough to move a full-size pickup through stop-and-go traffic without assistance from the gasoline engine, a trait that qualifies it as a full hybrid.

To minimize the V-8's fuel consumption, the two-mode system makes use of cylinder deactivation to shut down half the engine when full power is not needed. To compensate for the extra weight of the hybrid system and batteries, vehicle weight was reduced by using aluminum in the hood and front tailgates.

Finishing the Job of Redefining Hybrid

GM has been touting the superiority of its “two-mode” hybrid system for years. And for just as long, the company has made the point that more fuel can be collectively saved by improving the fuel economy of big gas guzzlers than by manufacturing smaller cars that are already relatively efficient.

The talk is over, and GM has finally delivered impressive results aimed at a new breed of hybrid customer. The company kicked off the release of the Yukon and Tahoe Hybrids at the Texas State Fair—not exactly traditional Prius country. Now it’s up to the company to make the vehicles widely available and affordably priced. 

The fine print on press releases for the Yukon and Tahoe Hybrid reads, “Limited availability in select markets starting fall 2007.” Prices have not yet been announced but are expected to be in the low- to mid-$40,000 range.

So despite the buzz, we’re still waiting for all the details on when and where we’ll see these new super-sized SUVs hit American roads. Until then, the buzz will continue. Karl Brauer, editor in chief at Edmund.com, told MSNBC, “The genie is out of the bottle. Americans have been spoiled with big, roomy utilitarian vehicles, and I don’t think they want to give them up, even with the price of gas going up.” Brauer believes that consumers don’t want to give up space, even while they seek better fuel efficiency. “The ultimate fulfillment of all these needs is a high-mileage, fuel-efficient SUV, and that is what GM is going after with these two SUVs.”