DANA POINT, CA – Despite numerous reports it would have one, the new Toyota Sienna minivan bows without a hybrid-electric drive system.

“(Debating) the cost benefit of the hybrid vs. where we are with (the) technology, we made the decision to offer a 4 cyl.,” Bob Carter, group vice president and general manager-Toyota Motor Sales U.S.A. Inc.’s Toyota Div. tells Ward’s at a backgrounder here for the new minivan.

“This is a large vehicle, it’s a little over 4,000 lbs. (1,814 kg),” he says of the new ’10 Sienna, going on sale in the U.S. in February.

Given the current state of hybrid technology, coupling an already heavy vehicle such as the Sienna with weighty batteries needed for energy storage would have reduced fuel-economy gains and made little economic sense, Carter says.

“There will be hybrid minivans in the future,” he says, noting Toyota’s strategy for making HEV technology optional on all models in its lineup by the 2020s.

But for now, Toyota’s all-aluminum 2.7L DOHC 4-cyl. engine, already offered in the Venza cross/utility vehicle, was the “way to go.”

Mated to a standard 6-speed automatic transmission, the mill makes 187 hp and 186 lb.-ft. (252 Nm) of torque in the Sienna.

Fuel economy with the 4-cyl. averages 22 mpg (10.7 L/100 km), up from 20 mpg (11.8 L/100 km) in more upscale front-drive Sienna with Toyota’s 266-hp, 3.5L V-6 engine. For ’10, Toyota offers the 4-cyl. only with front-drive base and LE Siennas.

No manufacturer markets a hybrid minivan in the U.S., but there are numerous larger vehicles outfitted with HEV systems, including the Toyota Highlander CUV, Lexus LS flagship sedan and fullsize SUVs and pickup trucks from General Motors Co.

However, most have decidedly non-minivan-like power and pricing.

The LS is heavier than the Sienna, at 5,203 lbs. (2,360 kg), but uses a 5.0L V-8 coupled with an electric motor to achieve a total 438 hp and a 21-mpg (11.2 L/100 km) average.

A ’10 Lexus LS 600h begins at $108,800.

GM’s hybrid Cadillac Escalade, Chevrolet Tahoe and GMC Yukon SUVs, as well as the Chevrolet Silverado/GMC Sierra pickups, use a pricey and complex 2-mode transmission technology, co-developed by GM, BMW AG and the former DaimlerChrysler AG.

The 2-mode Silverado, weighing in at 5,641 lbs. (2,559 kg) and with a 332-hp 6.0L V-8 engine, achieves an estimated 21/22 mpg city/highway with 2-wheel-drive models and a 20/20 mpg rating with 4-wheel-drive versions.

The 2-mode Silverado bases at just below $40,000.

A larger but more economical hybrid is Toyota’s Highlander CUV. The model, with total system horsepower of 270 from a 3.3L V-6 and two electric motors, returns an estimated 27/25 mpg (8.7/9.4 L/100 km) city/highway.

The Highlander Hybrid weighs 4,510-4,640 lbs. (2,046-2,105 kg) and begins just under $35,000, about the price of the ’10 Sienna XLE trim with all-wheel drive and a V-6 engine.

Toyota rival Honda Motor Co. Ltd. has said it is developing a full-hybrid system suitable for application in larger vehicles. The proposed HEV technology is similar to Toyota’s, capable of powering a vehicle solely on electricity under certain conditions.

However, Honda remains mum on when the new system will be introduced.