The Prius is the best-selling gas-electric hybrid in the United States and in the world. Toyota sold just 5,600 in 2001, but annual sales expanded to 54,000 in 2004 and 108,000 in 2005. Sales for the first quarter of 2008 were up from the same period in 2007.

Introduced as a 2001 model, the Prius was redesigned for 2004 and updated for 2006. The 2008 Prius gets some new options, notably leather upholstery and a leather-wrapped steering wheel.

We find the Prius to be a comfortable car that's easy to like and live with. It's roomy, with adult-size back seats and lots of cargo space. It's pleasant to look at, with sleek, futuristic styling, easy to spot in a parking lot. In short, we like the Prius.

The EPA ratings for the 2008 Prius are 48 mpg City, 45 mpg Highway, and we're guessing everyday fuel economy for most owners should fall somewhere between 40 and 50 mpg. The test procedure used until recently by the Federal Environmental Protection Agency exaggerated the fuel efficiency of all hybrids, but the EPA has revised its test procedures to more closely simulate modern driving habits.

While the Prius excels at fuel economy, its performance in terms of emissions is even better. Prius is certified as an Advanced Technology Partial Zero Emissions Vehicle (AT-PZEV); meaning that it meets the Super Ultra Low Emissions Vehicle (SULEV) exhaust standard; plus a zero evaporative emissions standard, a 150,000-mile durability demonstration, and an extended emissions system warranty. That makes the Prius an excellent choice for buyers who want to reduce air pollution and America's dependence on oil. The Prius isn't cheap, but it costs less than a lot of other vehicles that are commonly promoted as family transportation.

It's important to understand that the Prius is not an electric car. You never plug it in. And there's no worry about driving beyond the range of the battery. A small, highly efficient four-cylinder gasoline engine charges the battery as you drive. No special knowledge is needed to drive the Prius. It works just like a regular car: You get in, you twist the key, you put the lever in Drive and you go. When it gets low on gas, you fill it up.

The pinched-down nose is helpful for knifing through the air with little resistance. The quarter panels and doors are sleek and clean. The sole character line is a tasteful indentation in the lower region of the doors, visually connecting the creases marking the lower limits of the working area of the front and rear bumpers.

The side view makes clear its devotion to aerodynamics. A steeply raked windshield carries the hood's acute angle rearward. An even more steeply raked backlight (rear windscreen) ends in a high spoiler that trips the air stream as it leaves the car, maximizing the aero advantage of the car's almost-vertical back end. Sleek rear quarter windows do more to visually enhance the aerodynamic look than they do for outward visibility.

The 106-inch wheelbase contributes to a stable ride and interior room. But the Prius looks under-tired, almost as if the tires were left out when the rest of the car was made larger. The narrow tires help fuel ecnomy, but they clash visually with our current sense of proportion.

The headlights are compound units that house the running lights, side marker lights, turn indicators and, when ordered, fog lights. Vertically stacked compound taillights wear modish clear lenses and bookend the lower section of the liftgate. Integrated into the liftgate, and running its width beneath the rear spoiler, is a strip of glass adding critical rearward visibility for the driver.

Cargo space with the standard 60/40 folding rear seat in place is 14.4 cubic feet, comparable to that of a midsize sedan. The hatchback design makes its cargo area flexible.

The seats are comfortable for commutes and short weekend trips. Their forte is not the multi-hour, multi-state drive. The cloth upholstery looks durable and is grippy, compensating somewhat for the minimalist bottom and back side bolsters. Head restraints are adjustable in all five seating positions. The interior finish is up to Toyota standards, with pleasingly close tolerances between body panels and interior plastic pieces, and plastics that look and feel better than the word plastic connotes.

The speedometer, fuel gauge, trip meter, and transmission selection indicator are tucked into a long, flat, eyebrow-like opening draped across and centered on the top of the dash where it meets the windshield. The primary gauges are located in the left half of the opening, but are closer to the centerline of the car than to the driver.

Climate controls are managed via an LCD screen at the top of the center stack. This panel also displays user preferences and maintenance needs. Most entertaining, however, is that it allows tracking of the power and recharging flows, monitoring battery and gasoline usage. And it serves as the focal point for the optional navigation system.

Directly beneath the screen is the control head for the sound system. Toyota deserves high praise for keeping the stereo's most-used functions outside of the onboard computer's labyrinth and, equally important, for giving it buttons and knobs that are easy to see, read and use. The base AM/FM/CD six-speaker sound system is quite capable. We'd have been better able to enjoy the premium JBL system to its fullest if there had been a bit more sound deadening in the floorpan and doors, but sound deadening adds weight, the enemy of fuel economy.

Remote switches for the audio, climate and cruise controls are conveniently mounted on the steering wheel. There are two standard accessory power outlets. Dome lights grace the headliner, front and rear. Both sun visors have illuminated vanity mirrors. These may seem small matters, but they distinguish between value and cheap.

A tall glasshouse yields exemplary outward visibility. But as is the case with many of the latest aerodynamic designs, the driver can't see the front of the car or the hood without leaning forward.

Storage spaces are abundant and flexible. The glove box is a two-parter, with an upper and lower bin opening like a clamshell. The upper glove box is good for long, narrow items, like gloves. The lower compartment holds bulkier items. The front part of the center console opens up, also clamshell-like, into two cup holders. Door-mounted map pockets, expandable magazine holders stitched into the back of the front seat backs, and an unexpected, semi-secluded bin below the stereo offer additional storage.

Two cup holders pop out of the rear of the console for back-seat riders. An armrest folds down out of the rear seat back. The rear seats are split 60/40, each part of which folds to yield an almost-flat floor, without having to remove the head restraints. There are hidden spaces beneath the cargo floor, both below and on top of the mini-spare.

Gas pressurized struts ease opening and closing the hatchback. Doors close with a solid, if not truly impressive clunk; then again, weight savings have to come from somewhere.

Standing on the accelerator produces a pleasant surprise. The Prius launches without hesitation thanks to the electric motor's 295 pound-feet of torque from almost a dead standstill. Merging and overtaking at freeways speeds are accomplished with little fuss. Those wishing to experience the car's outer limits, however, should expect more leisurely progress to a top speed of around 100 miles per hour. Speeding calls for horsepower, and as the Prius approaches its maximum velocity, it relies increasingly on its small gasoline engine for motivation. Toyota says the Prius can accelerate from 0-60 mph in about 10 seconds, anemic by modern expectations, but then we've come to expect a lot. As recently as the mid-1950s, legends like the Chrysler 300 and Buick Century didn't reach 60 mph much quicker than that.

Prius gets its power from a gasoline engine supplemented by an electric motor. In a bit of hyperbole, Toyota calls the combination the Hybrid Synergy Drive. Hybrid it is, synergistic it isn't, not by the strictest definition of the word, which would mean that the total power output would be more than the sum of the outputs of the gas and electric motors individually. This is not the case. The Hybrid Synergy Drive does, however, rely on its electric motor more than do most other hybrids, including the first-generation Prius; as a result, Toyota claims the Prius produces about one-tenth as much pollution as the average new car. Toyota seems way out in front of everyone in this technology. To us, Toyota's hybrid system seems more like an electric motor with gasoline engine assist, while Honda's system seems more like a gasoline engine with electric motor assist.

By complementing the gasoline engine's horsepower with the electric motor's torque, the Prius makes better use of the energy stored in each gallon of gasoline, while leaving fewer nasty chemical compounds in its wake. The electric motor, which begins cranking out its maximum torque virtually the moment it starts spinning, gets the car moving and helps it accelerate while it's underway. The gasoline engine steps to the fore at more constant speeds, especially during highway driving, where horsepower is more critical for maintaining a car's momentum.

The hybrid system improves fuel economy further by turning off the gasoline engine when it's not needed, like when you are waiting at a stop light or even when puttering around town at low speeds. Any time the driver's right foot requests more motivation than the electric motor alone can provide, the gasoline engine fires up and joins in.

The transmission is non-traditional, too. The electric motor itself, combined with a planetary gear set, functions much like a continuously variable transmission. This system constantly and automatically selects the most efficient drive ratio to get the car moving and to keep it moving.

The Prius also saves fuel and reduces emissions by scavenging energy that most cars waste. Regenerative braking links the brakes to a generator, helping use the car's kinetic energy to recharge the battery whenever the brakes are applied. Along the same lines, the transmission offers a setting that helps recharge the battery when the driver merely lifts off the accelerator and lets the car coast, most beneficially downhill.

Previous EPA ratings for the Prius generated controversy. But remember that EPA tests cars on a chassis dynamometer, that is, a set of rollers in the floor, which work against an electric or hydraulic resistance. Wind resistance for the stationary vehicle is estimated. The electric motor plays a bigger role in these laboratory conditions than it does in the real world and, in one of those strange twists of logic often produced by law, Toyota was and is legally barred from advertising any mileage numbers other than those released by the federal government.

But while the EPA has not fundamentally changed its procedure, it has significantly revised it to produce something closer to real-world results. The EPA's current numbers for the Prius, 48 mpg city, 45 highway, and 46 combined are in line with published reports, and with what we have heard from actual owners.

Emissions are the lowest of any real car widely available to U.S. buyers. You might think the Prius would be bettered by a purely electric car, but a pure electric must be recharged using another energy source that, in turn, requires fuel, often coal. So in the big picture, the Prius may well be easier on the environment than even a pure, plug-in electric car.

The Prius rides on regular, commonly available tires. They are not sporty treads, so don't look for quick and precise left-right transitions. But they are stickier than we expected. Some tire noise is evident, no doubt because Toyota skipped some sound insulation in the interest of saving weight. But wind noise is nicely subdued by the car's impressive aerodynamics.

Braking is linear, thanks to enhanced algorhithms in the computer that manages this system. They have made brake feedback more natural, so the brakes don't feel as obviously assisted and as if they were managed somewhere else. Tapping the dash-mounted shift lever to engage the B function (for engine braking) returns a feel much like engine compression braking, as if the driver had dropped down a gear while slowing.

Four adults seem to be about the limit for the soft rear suspension, compressing it to the point where occupants will feel the bump stops on mildly rough pavement. And this is without any luggage. The Prius rides better with two adults and two kids.

Standard features include fabric upholstery; electric air conditioning with a micron filter; power windows, door locks and heated outside mirrors; remote keyless entry; cruise control; a tilting steering wheel with redundant climate and audio controls; intermittent front and rear wipers; a six-speaker AM/FM/CD stereo; and P185/65 all-season tires on 15-inch aluminum wheels.

The Touring Edition rides on a more tautly tuned suspension and P195/55R16 wheels and tires. Visually, it's distinguished by HID headlamps with integrated fog lamps, and a larger rear spoiler.

Options are bundled into packages, with each succeedingly numbered package building on the contents of the previous packages. Package 1 comes standard. Package 2 ($575) includes vehicle stability control (VSC), a reversing camera to help you see what's behind you, Smart Key access, and MP3 capability for the stereo. Package 3 ($2,105) adds a premium nine-speaker JBL stereo with CD changer and Bluetooth; and Homelink. Package 4 ($2,580) adds HID headlamps with foglamps and a security alarm. Package 5 ($3,280) adds navigation. Package 6 ($4,550) tops it all off with leather seats and a leather-wrapped steering wheel.

Safety equipment that comes standard includes antilock brakes (ABS), Electronic Brake-force Distribution (EBD), Brake Assist, and traction control. Standard passive safety features include advanced multi-stage, dual front airbags; side-curtain airbags designed to offer head protection for front and rear passengers; seat-mounted side-impact airbags for torso protection for driver and front-seat passenger; three-point seatbelts and head restraints at all five seating positions; and rear seat head restraints that are adjustable. A tire pressure monitoring system comes standard.