These latest-generation Porsche 997s feed information back to the driver just a little more clearly and react to commands a nanosecond sooner than the previous generation. They also retain the wash-and-wear quality that has made the 911 a relatively easy car to live with everyday.

The standard Carrera and Carrera 4 are powered by a revised version of Porsche's familiar 3.6-liter, horizontally opposed six cylinder, otherwise known as the boxer engine for the way its pistons punch outward. It employs the latest materials technology, a race-car style dry sump lubrication system and a refined version of Porsche's VarioCam variable valve timing. Horsepower peaks at 325, while peak torque remains 273 pound-feet. Yet the updated engine is lighter, with lower fuel consumption at a given rpm and fewer exhaust emissions.

Our test car was a Carrera S with a new (for 2005), slightly larger version of the boxer engine. The extra displacement from the 3.8-liter engine pays off in a substantial increase to 355 horsepower and 295 pound-feet of torque. The 3.8-liter shaves about 0.2 seconds off the standard Carrera's 0-60 times.

Even before the improvements, the 911's engine was one of the most tractable found in a sports car. The improved engines in the newest Carreras take this outstanding balance to new heights.

Most drivers care less about specific technologies or how they work and more about what those technologies do. Anyone with a bit of experience in a wide array of cars will grasp the benefit of VarioCam. Ten years ago, high performance engines required more significant trade offs. Build them with good low-end power so they made the car jump with authority from a start and they would likely run out of steam at higher rpm, coughing and wheezing as they approached the redline on the tachometer. Build them to spin like a turbine at higher revs, breathing like a sprinter and building velocity through the higher range, and they were likely anemic off the line. Variable valve timing allows engineers to better achieve the best of both worlds: good low end punch, free breathing at high revs. These Porsche engines deliver this combination better than just about any on the market.

Acceleration? We easily managed 0-60 mph runs under 4.5 seconds, measured with a portable, over-the-counter accelerometer. That's easily half a second quicker than a car like Audi's S4, which happens to be one of most capable, potent high-performance luxury sedans you can buy. In automotive terms you can do a lot in half a second.

However, these figures only hint at the satisfaction a driver can find in the 911's engine. The real draw lies in its tractability. Slam the 911's gas pedal at any road or engine speed, and the response is immediate, not to mention enormous. There's more speed available in just about any situation, rumbling up through the driver's backside and into the belly. We wanted to floor it every time we tracked through a turn and let the engine wind to its 7300-rpm redline, just to feel the acceleration and listen to the unmistakable rasp of a Porsche boxer engine (the best one yet). Anyone with a pulse should appreciate the visceral exhilaration built into the 911.

Acceleration is only one component of the 911's impressive performance. Porsche's engineers devoted significant energy to trimming the Carrera's weight in an effort to compensate for new, weight-increasing equipment like head-protection airbags. The steering system, suspension and attachment points have been redesigned with sturdier, lighter components, reducing unsprung weight. The Carrera's track has been widened for more lateral stability. In total, the changes make what was already one of the nimblest, most responsive cars on the road more so.

Our Carrera S had Porsche's Active Suspension Management system (PASM). Managed by an electronic control system, PASM controls the flow of hydraulic fluid into the 911's shock absorbers. More fluid, and the shocks stiffen up, keeping the wheels pressed more aggressively to the pavement and limiting the amount of body roll, or lean, in hard turns. Less fluid, and the wheels rebound more easily toward the car, improving ride quality.

Porsche Active Suspension Management takes information from various electronic sensors and automatically adjusts the suspension to meet a driver's demands. Motoring casually along a boulevard, the active suspension will keep things relatively soft. If a driver gets more aggressive and starts changing directions quickly, on a slalom course, for example, the system senses the change and instantly firms the suspension. The driver can also manually select one of two modes: Normal, for maximum ride comfort, and Sport, for the best handling response. Porsche claims that, with the system in fully automatic mode and its best test drivers at the wheel, a Carrera with the active suspension can lap the famed Nurburgring five seconds faster than one with the standard suspension. The Nurburbring is a treacherous, 12-mile circuit in a remote corner of Germany once used for international auto races and now primarily a development track for international automakers.

With variable ratio steering, the more the driver turns the steering wheel, the faster the car turns. For 30 degrees either side of the center, movement on the steering wheel turns the front tires at a more moderate rate. Beyond 30 degrees, say with the top of the steering wheel turned down toward the bottom, inputs on the wheel turn the tires faster. Variable ratio steering is another one of those systems intended to deliver the best of two worlds. On one hand, it's supposed to ease maneuvering in the confines of a tight parking lot, or improve response on a winding road with frequent sharp turns. On the other, it should improve stability at ultra-high speeds. A driver who sneezes during a 150-mph blitz down the autobahn doesn't want a little twitch of the hand to send the car into the adjacent lane. Enthusiast drivers tend not to like high-tech steering gizmos like variable-ratio steering. The active steering system that BMW has introduced in its 5 Series sedan, for example, has not been widely praised. Yet Porsche's less-complicated variable system works just fine. It's seamless, linear and predictable, and with a little familiarization, the Carrera's steering feels as pure and satisfying as any 911 before it.

Indeed, one of the most remarkable things about this car is the way it accurately follows the path the driver sets. With reasonable attention, a driver can put the 911's front tires within a fraction of an inch of the intended target, whether that target is the apex of a curve on a racetrack or a stripe painted on a public road. The 911 will track more accurately in this fashion, more consistently, than just about any car you can buy, and required steering corrections are minimal, even when a bump or pothole wants to slam the Carrera off its intended path. Moreover, even with the new variable-ratio, the 911's steering communicates every nuance back to the operator. A skilled driver can tell, just by feedback through the steering column, how close the front tires are to loosing their grip and sliding.

Grip is in abundance and the 911 tenaciously sticks to the pavement through high-g turns. This kind of performance is expected in a high-priced sports car, to be sure. Yet the great thing about the 911 is that it doesn't beat you up in more mundane driving situations, as we found running out for a quick lunch through the cratered streets of downtown Detroit. It's part of what we call the 911's wash-and-wear quality. As high performance machines go, its ride is remarkably comfortable, with very little suspension crashing and very few jolts through the body of the car. The active suspension only enhances this quality. Even during aggressive drives, there's enough compliance in the suspension to keep the Carrera on track when it hits a bump, including a bump that would send other sports cars off line and require steering correction.

The 911's infamous tail-happy handling, a function of the weight of the engine hanging off the back of the car, is ancient history. It now takes work to get the Carrera's rear end to slide out. It prefers to stay on the intended trajectory, even if the driver provokes it with some ham-handed inputs on the steering wheel or gas pedal. Trailing-throttle oversteer, which in the past got inexperienced drivers into trouble, is not an issue on the modern 911. The all-wheel-drive Carrera 4 models employ a viscous-coupling to send from 5 percent to 40 percent of the driving force to the front wheels as needed. This is an advantage especially in bad weather, where you need all the grip you can get. But even dry pavement handling is improved, expanding the 911's already impressive performance envelope.

In other words, this sports car truly inspires confidence. Some cars of its ilk require at least a small leap of faith from the driver. You can hustle them through a high-speed curve on a race track, and they'll stick like putty and carry a ton of speed out of the other end. But as you turn in and then jab the gas pedal at the apex, you'll pucker a bit and mentally cross your fingers. The 911 requires no such self-convincing. You're quite sure that with a reasonable dose of common sense, it will get you through. It can make the average driver feel like a pro, and it can make drivers who like to work on their high-performance skills feel like Hans Stuck.

The Carrera's brakes only enhance that confidence. Stomp the pedal: the 911 leans forward just a hair and stops, now, in less distance than just about any car on the road. Stomp the pedal again, and again and again. Whether lapping a road course or barreling down a mountain road, there is no perceptible fade or increase in stopping distance, even in situations that would have the brakes on lesser cars smoking. And if you jerk the wheel in one direction or the other in one of those stops, the 911 will just turn. No fuss, no fluster.

What do we mean when we say that the 911 has devolved? It's hard to pinpoint exactly. Some might say the car is rougher, but we like it better. The manual shifter, for example, has shorter throws, but it is also a bit stiffer to operate, and more mechanical in its feel. There's a bit more vibration rising up through the steering column and coursing through the spine down the center of the car. The rasp of the exhaust may be just a hint louder. Whether these subtle adjustments are a deliberate response to those who claimed the 911 was getting too soft, or part of Porsche's continuing quest to increase performance or reduce weight, we're not sure. What matters is that this feedback helps the driver feel more connected to the machinery. We wouldn't have guessed that was possible two years ago, when we last drove the previous-generation Porsche 911, a 2004 model.

Still, the 911 retains its basic, user-friendly attitude. A driver need not even master the art of manual shifting to fully exploit or appreciate this car's potential. Porsche's Tiptronic automatic remains one of the best compromises between the involvement of a manual shifting and the convenience of a full automatic. Put it in drive for the rush hour commute and forget it. It's a lot easier on the left leg in the stop-and-go, a compelling feature for drivers who run the rat race every day. Flick the shift lever to manual toggle mode when the traffic thins, and select the preferred gear almost as quickly and responsively as a clutch-operated manual.

With the caveat that storage space is limited, the 911 remains one of the easiest high-performance sports cars to get in and out of, and the easiest to live with every day. The new engine has no dipstick for the oil, for example. The oil level is displayed electronically on the dash every time the car is started. Thanks to new technologies, materials and lubricants, nearly every scheduled maintenance interval has been lengthened, and that should increase convenience and reduce the cost of ownership. The maximum oil-change interval for the Carrera is an almost unbelievable 20,000 miles. In 1975, a conscientious 911 owner would have changed the oil six or seven times in that period.

Last but not least, while the new Carrera engines are more powerful, they are also more fuel efficient. EPA mileage ratings are 1 mpg improved over the previous generation, which also means reduced exhaust emissions.