Boston.com's view

What’s small on the outside, big on the inside, and green all over?

No, not a skinny frat boy who had too much beer, too much pizza, and wakes up the next morning queasy and wondering where he got the clothes he’s wearing.

It’s the Toyota Prius, one of the first of what will be many hybrid gasoline-electric vehicles to go on sale here in the next five years.

It is the first full-size – five passengers, quite comfortably, thank you – hybrid to go on sale. Already, nearly 40,000 have been sold in Japan and, by the end of next year, nearly 15,000 could be rolling American roads.

I drove Honda’s entry into this field – the Insight – some months ago, and found that little two-seater to be a remarkable commuter car that felt like a standard gasoline-powered auto. The Prius I drove back then was a Japan-rigged prototype and, right-hand-drive aside, I found it too gimmicky and not that smooth.

The new American-standard Prius, however, was a vast improvement. You could feel when the gasoline motor kicked in or out to charge the electric or let the electric do the work, but it was a smooth, seamless affair.

I like to talk about burbles and rumbles when I talk about high-performance cars. Now comes the hybrid, and whir and hum will have to become a part of my vocabulary. Already, Honda plans a hybrid Civic, Dodge promises a Durango, and other American manufacturers are lining up to build hybrids.

The Insight proves they can be remarkably efficient – 60-80 miles per gallon. Prius proves they can be that – I got 46 miles per gallon with no attempt at conserving fuel – and roomy. Five people sit in its high, spacious interior in broad comfort. Front seat space is created because the dash is cut away in front of driver and passenger. A hump in the middle of the dash holds the electronic goodies – notably, the display that, among other things, shows you how hard your gasoline engine and electric motor are working, and where the power each generates is going.

The latter is essential because this is a car with an electric motor that never has to be plugged in. Sometimes, the electric motor acts as a generator and recharges its own batteries. Sometimes, the gasoline motor runs a generator that recharges the batteries. Sometimes, each is working even as they feed the batteries.

It all adds up to estimated mileage of 52 miles per gallon in the city and 45 on the highway. The former figure is higher because, in the city, the electric motor is more consistently in play, yet, every time you hit the brakes or slow down, a ”regenerative braking” system can provide the batteries with more power than they are losing.

The result is a Super Ultra Low Emissions Vehicle – any cleaner and it would be burning city smog and spitting out pure oxygen.

The gasoline engine, a 1.5-liter, four-cylinder powerplant, delivers 70 horsepower. The electric motor provides 44 horsepower, but, as electic motors will do, lots of torque – 258 l b.-ft. in the Prius.

Here’s how they work in their ”cross-parallel” configuration.

In initial acceleration at a moderate rate, the electric motor does the work. The gasoline engine kicks in for heavy acceleration.

In city driving, the engine and motor share the load, and when you are rolling along, you sometimes hear the gasoline engine go silent.

On the highway, the gasoline engine does the work though the electric motor will provide boost for passing.

On hills, the electric motor draws from both the battery pack and the generator while the gasoline engine fuels the battery pack and provides power to the wheels.

In coasting and braking, the electric motor acts as a generator to refill the batteries.

The operation is smooth and, unless you pay attention to the inboard display, you forget you are driving something different.

It’s the same way with the transmission, a continuously variable tranny – mounted on the dash, pick forward or reverse – whose op n is remarkably smooth.

The Prius is not a stripped-down, hell-bent-for-economy rig. It comes standard with a four-speaker sound system, tilt steering wheel, air conditioning, power windows, door locks and mirrors, ABS, front air bag, and halogen headlamps.

It is comfortable on the road, hugs reasonably well through corners, and moves nimbly even in the passing lane on the highway. It is obvious from its response to the gas pedal that it could cruise a highway out West at 85 miles per hour and top 100 miles per hour with reasonable ease.

The smooth ride – just a bit of body roll, but the high headroom is worth it – comes from a relatively simple suspension system. It’s got an independent strut/stabilizer bar configuration up front, a torsion beam with stabilizer bar in the rear.

Hybrids are coming in all their facets, from the two-seater Insight, to comfortable small sedans like the Prius, to a larger sedan from General Motors to SUVs and, from Volvo, a full-blown big rig for the cross-country trucking crowd.

They may not all be small on the outside or big on the inside, but all will be greener.

Nice touches:

The great number of nooks and crannies for storage.

The broad, high doors. Easy in and out on this car.

Annoyance:

Wish they had been a little more dynamic (read less Echo-ish) in their exterior styling. Just a little something to set this one apart.