An auto maker redesigning one of its best-selling models must proceed with caution.

If the next-generation vehicle is too radical a departure, the company risks a backlash.

Play it safe, though, and it invites accusations of being too conservative. The higher the volume, the more intense the pressure to get it right. Toyota Motor Corp. understands this in redesigning the Camry, America's best-selling passenger car for eight of the past nine years.

Although the '07 Camry looks very different from its predecessor, it is easy to see contemporary mass-market design influences in the vehicle's front (Mazda6, Toyota's own Avalon) and rear (Hyundai Sonata, Toyota's Lexus IS).

The new Camry's profile almost is unchanged from the outgoing fifth-generation model. In other words, this is no Chrysler 300-esque rip-up of the rules.

What is new for the Camry lineup is the addition of the Camry Hybrid.

The hybrid-electric vehicle variant marks the first time Toyota has applied its Hybrid Synergy Drive HEV technology to an existing high-volume model.

Toyota has mated an Atkinson-cycle 2.4L gasoline 4-cyl. to an electric motor that, together, can deliver a combined 192 hp to the front wheels.

As with its other HEVs — the Prius, Highlander and Lexus RX 400h — the transmission is an electronically controlled continuously variable type.

Fuel economy is estimated at 43 mpg (5.5 L/100 km) city/37 mpg (6.4 L/100 km) highway, and Toyota says a New York-to-Los Angeles road trip in 2004 by the vehicle's chief engineer produced 36 mpg (6.5 L/100 km) overall, with cruising speeds of 75 mph (121 km/h).

In mixed driving in Ojai, CA, the Camry Hybrid's fuel economy was in the mid-30 mpg (7.8L/100 km) range.

For those wishing to save more fuel, Toyota has installed what it calls an ECO (for Economy and Ecology) button, which lengthens the amount of time it takes for the air-conditioning system to cool the cabin and prevents the gasoline engine from running the heater when the vehicle is stopped.

Typically, the Hybrid Synergy Drive is programmed to shut down the IC engine when the car is stationary. The ECO button seems like a gimmick, and it will be difficult to quantify fuel-economy gains.

Driving the Camry Hybrid was somewhat disappointing. While the Hybrid Synergy Drive is a technological marvel, it also is becoming predictable.

Tap the brakes, and the Camry Hybrid nosedives just like Toyota's other HEVs. And, with just a 4-cyl., the HEV lumbers through sporty driving as if it needs a nap.

While it initially makes sense to install a fuel efficient 4-cyl. rather than a V-6, as competitor Honda Motor Co. Ltd. does with its Accord Hybrid, for Toyota, the driving experience is not terribly impressive when matched with such a heavy car.

At 3,637 lbs. (1,650 kg), the Camry Hybrid is 352 lbs. (160 kg) heavier than Camry's CE and LE trims with a 5-speed manual, and a significant 136 lbs. (62 kg) heavier than Honda's Accord Hybrid.

However, the Camry Hybrid's HEV system is capable of propelling it under electric power only — the Accord Hybrid's Integrated Motor Assist system does not offer that option.

The price of the Camry Hybrid, from Toyota's indications, likely will be in the upper $20,000 range, not far off the Accord Hybrid's $30,140 sticker.

But Toyota is not Honda, and Toyota's HEVs seem to sell themselves, while Honda's linger on dealer lots.

Toyota claimed last November there were about 40,000 initial hand-raisers for the Camry Hybrid; it intends to build 48,000 annually at its Georgetown, KY, plant.

For all its technology, the Camry Hybrid cannot measure up to the driving experience offered by the lowest-priced entrant in the Camry lineup for '07, the new base CE model, or the sporty SE.

These are the Camrys Toyota should be touting. Toyota was able to squeeze out 4 more hp and 1 more lb.-ft. (1.4 Nm) of torque from the Camry's base 2.4L 4-cyl. (non-Atkinson), for ratings of 158 hp and 161 lb.-ft. (218 Nm).

Mated to the carryover 5-speed manual or the 5-speed automatic Toyota used to couple only with the previous-generation Camry's V-6, the 2.4L variable-valve-timing 4-cyl. is surprisingly robust.

For a base trim level, the CE comes well-equipped, with standard features such as power windows and door locks, a tire-pressure monitoring system, seven airbags and antilock brakes.

Fuel economy is good, at 25 mpg (9.4 L/100 km) city and 34 mpg (6.9L/100 km) highway with the manual and 1 mpg less in each drive mode when paired with the 5-speed automatic.

Most customers do not buy a Camry because they expect an exhilarating ride, but the SE trim at least plays on the same turf as the overtly sportier Nissan Altima and Mazda6. In a spirited run through the twisties, the Camry SE is up to the task.

Toyota used sportier shocks, springs, anti-roll bars and bushings to tie down the suspension and also lowered the SE's ride height by 0.4 ins. (1 cm). There is even a V-shaped chassis brace between the car's trunk and cabin. These are somewhat serious measures for a family sedan.

The SE builds on the standard features of the CE by adding an 8-way power driver's seat, dual exhaust for V-6 models and remote keyless entry.

Also standard on the SE are 17-in. aluminum alloy wheels and leather-wrapped steering wheel and shift knob.

The V-6, meanwhile, is the 2GR-FE 3.5L DOHC unit now making its way throughout Toyota's model range to replace the old 3L and 3.3L V-6s. For the '07 Camry, it makes 268 hp and 248 lb.-ft. (336 Nm) of torque. It is coupled only to a 6-speed automatic, a first for Camry.

The middle of the road LE trim, which Toyota expects to capture 60% of this year's volume, offers the 4-cyl. or the V-6. The high-end XLE trim comes standard with the new V-6 and 6-speed automatic.

A 3.5L V-6 option is certainly warranted in a vehicle such as the Camry (midsize-sedan competitors offer V-6 power, too), but do most customers seeking a middle-market sedan really need 268 hp for a power run to the mall or day-care center?

Nevertheless, fuel economy is improved with the new V-6: 22 mpg (10.7 L/100 km) city/31 mpg (7.6 L/100 km) highway vs. 20/28 (11.8/8.4 L/100 km) for the old 3.3L V-6, which means the added 58 hp from the new 3.5L comes, in a sense, with no penalty.

Toyota has not increased interior volume compared with the outgoing Camry. But through various tricks, such as pushing the bottom of the windshield forward, engineers were able to achieve a more spacious feeling.

Rear-seat passengers get an extra half-inch (1.2 cm) of legroom, and in the XLE trim, rear seatbacks can be reclined 8 degrees.

Besides a full redesign of the Camry's dash and console, new materials are present, such as the soft Fraichir (pronounced fray-sheer) seat fabric for the XLE , which is treated with a product known as Sericin, extracted from silkworm cocoons. The quality of the Camry's leather is exceptional, with luscious stitching detail.

Fit and finish is outstanding, as Toyota always is a stickler in this respect. But certain design elements seem out of place, such as pairing bird's-eye maple trim with rental-car gray plastics.

And while user-friendly, the top of the new 2-level dash is vast and monotonous.

Plus, Toyota dipped into the Corolla parts bin for the Camry's mirror and fuel-door release buttons, as well as other minor components such as headliner fabric and plastic trim.

Still, few Camry loyalists will notice. Most people buy this nameplate for one reason: quality.

Besides the sticky engine-sludge issue of a few years ago, Toyota has made rare missteps with its best-selling car.

However, as noted by Toyota more than once at the media preview, the midsize sedan segment in the U.S. is big and growing.

Soon, other auto makers, possibly Hyundai Motor Co. Ltd., will replicate the successful formula Toyota has created with the Camry.

The 4-cyl. Camry is a perfect way to keep them at bay, but the Camry Hybrid and overpowered V-6 models suggest Toyota is trying too hard to continually raise the bar for wannabe competitors.

'07 Toyota Camry SE (V-6)

Vehicle type: Front-engine, front-wheel drive, 5-passenger 4-door sedan

Engine: 3.5L (3,456 cc) DOHC V-6, aluminum block/aluminum heads

Power (SAE net): 268 hp @ 6,200 rpm

Torque: 248 lb.-ft. (336 Nm) @ 4,700 rpm

Compression ratio: 10.8:1

Bore × stroke (mm): 94 × 83

Transmission: 6-speed automatic

Wheelbase: 109.3 ins. (278 cm)

Overall length: 189.2 ins. (481 cm)

Overall width: 71.7 ins. (182 cm)

Overall height: 57.5 ins. (146 cm)

Curb weight: 3,485 lbs. (1,581 kg)

EPA fuel economy, city/highway (mpg): 21/31

Market competition: Chevrolet Impala; Ford Fusion; Honda Accord; Hyundai Sonata; Nissan Altima