The Toyota Prius may be the most popular hybrid model of the many Toyota sells.

But the company's largest hybrid vehicle weighs more than six new 2014 Prius Liftbacks when it's fully loaded.

It's the Hino 195h, a 7- to 9-ton diesel-electric Class 5 commercial truck known as a "cab-over," meaning its cab sits directly over the engine. Its gross vehicle weight is 19,500 pounds.

Hino is Toyota's commercial truck brand, which has sold trucks in the U.S. since 1984.

The Hino 195b hybrid truck--as well as a conventional diesel-only model--went on sale in January 2012, and was Hino's first light-duty truck sold in the U.S. since 2004. It's offered in both conventional and crew-cab models.

Hino 195h diesel-electric hybrid Class 5 cab-over-engine truck

Hino 195h diesel-electric hybrid Class 5 cab-over-engine truck

The company's engineers are said to have developed the hybrid truck--known in Japan as the Dutro--independently of their automotive colleagues at Toyota.

Indeed, the Hino's hybrid uses a single 36-kilowatt (48-horsepower) electric motor mounted between the 210-hp 5-liter five-cylinder diesel engine and the six-speed automatic transmission.

That's quite different from the layout of the automotive Hybrid Synergy Drive system, which has two electric-motor generators and a planetary gear set to provide various combinations of engine and electric motor torque output and battery recharging during regenerative braking.

The engine puts out 440 lb-ft of torque, while the electric motor can produce 258 lb-ft on its own.

Still, the Hino's 1.9-kilowatt-hour nickel-metal-hydride battery pack is the same one used in the very low-volume Lexus LS 600h hybrid full-size luxury sedan. And just like the Prius, there's an "Eco" mode button in the cabin.

The hybrid model isn't as effective for delivery vehicles that do a lot of highway miles, but in more congested locations with a lot of stop-and-go traffic, it can save a considerable amount of diesel fuel.

According to Hino, the 195b gets fuel economy that's as much as 30 percent higher than that of the standard diesel model. (There are no EPA fuel-efficiency ratings for large trucks.)

Some analysts think the market for hybrid commercial vehicles faces a strong challenge from natural-gas powered trucks, although over the next decade, alternative powertrains will grow strongly for commercial vehicles.

Meanwhile, the next time someone tells you hybrids are wimpy, point that person toward this truck.

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