The Good: The 2009 Audi S8 offers a good bundle of driver aids, including adaptive cruise control and blind spot detection. It has a good iPod interface, an excellent Bluetooth cell phone system, and an exceptional stereo--with the right kind of music. Its Quattro all-wheel-drive and air suspension deliver good control. The Bad: The navigation system is badly in need of an update and offers no advanced features. Fuel economy is abysmal. The Bottom Line: The 2009 Audi S8 is a very powerful big sedan with some excellent handling features, but it doesn't offer all of the latest in-dash gizmos, and you trade a luxury ride for performance. Photo gallery: 2009 Audi S8The A8 is Audi's flagship sedan, the top of the pile, the king of the mountain, but the company does itself one better with the 2009 Audi S8, an amped-up version of its big luxury car designed to throw a little thrill toward those well-heeled enough to afford such a car. The S8 gets the same engine as the new R8 V-10, Audi's Quattro all-wheel-drive system, and an air suspension designed for aggressive driving. Sport touches abound in the car, too, with carbon fiber cabin trim and S8 logos on the tachometer, rocker panels, and front brake calipers. Our Audi S8 also served as a test pad for a set of driver aid features that included blind spot assistance, adaptive cruise control, and lane departure warning system, this last feature being new for Audi. We were also quite pleased to see the Bang & Olufsen audio system we enjoyed so much in the Audi A8. On the road Immediately after getting onto the freeway in the big S8, we were enveloped in traffic, with cars darting across lanes so that we didn't want to try the adaptive cruise control just yet. But the blind spot detection feature made an immediate difference, lighting up a warning in the side mirror casings whenever a car hung off our rear quarter. Although we had 450 horsepower ready to go, cars in front and to the sides kept us locked into place, so we took stock of the other treats the S8 had to offer. The blind spot detection system lights up when a car is off the S8's rear quarter.We paired an iPhone to the car's Bluetooth system, and were able to pick names from the contact list right on the S8's screen. That same iPhone was docked to the car's iPod jack, resulting in our full music library being accessible using Audi's Multimedia Interface, a knob on the console. And music was being played through the premium Bang & Olufsen audio system, which pumps over 1,000 watts of power through 14 speakers. This system makes sweet, sweet sound, delivering ultimate clarity and letting you hear your music like never before. It's a true audiophile's system, but it requires music up to its standards. Don't feed it MP3 tracks--the faults of compressed audio become abundantly clear. It wants lossless audio, either full CDs or tracks ripped to a lossless format. After time spent enjoying these aspects of the car, traffic lightened up and we were able to make some use of the car. Bearing down on the gas we didn't feel a big push, like we expected from this engine, but a glance down at the speedometer showed the S8 picked up an immense amount of speed subtly, keeping the g-forces minimal in the cabin. The V-10 engine is hooked up to a six-speed automatic transmission, which didn't seem completely up to the task. In standard drive mode, moving along at 65 mph, the tachometer ticked up to 2,500rpm with the transmission in its top, sixth gear. Putting the transmission into manual mode and using the paddles to shift, the engine's growl became audible in fourth gear, and absolutely ferocious in third. We weren't going to risk second. Engaging the adaptive cruise control was a confusing process, as the instructions and controls are on a stalk obscured by the left spoke of the steering wheel. After some trial and error we set it to 80 mph, marked by a red LED on the speedometer. The S8 followed the car ahead like it was on an elastic band, giving some smooth acceleration when the car sped up, then dropping back when it slowed down. At one point, traffic bunched up and the S8 slowed quickly, applying its own brakes. Driving out into the wilds of the Sacramento Delta we find an excellent photo opportunity.When we had enough of freeway driving, we put the S8 onto a two lane highway, and subjected it to an impromptu acceleration test. According to Audi, the S8 hits 60 mph in 4.9 seconds. The S8 didn't exactly bolt off the line, as its Quattro and road-holding electronics did some quick computing after we hit the gas, deciding how much power the S8 could take without losing grip. Although there was no tire-spinning fury, the V-10 overcame the car's inertia rapidly enough, and it hit 60 mph right around 5 seconds, according to our count. We found the S8 a real powerhouse, with plenty of useful electronics. But its responses feel just a little slow. However, Quattro and other systems gave us confidence that the S8 would prove safe and reliable during inclement weather. In the cabin Inside the car, a lot of carbon fiber and fine stitched leather surrounded us, all due to options that helped this 2009 Audi S8 top the $100,000 mark by a significant amount. These expensive materials were offset by Audi's standard switchgear, which included the metal MMI knob, various plastic buttons around the console and control panel, and Audi's standard steering wheel rollers and buttons. We actually do like these controllers, but you can get the same in the A4. Seems like a car of the S8's caliber should be distinct in every detail. The maps look decent enough, but the navigation system lets the car down.This complaint also lends itself to the navigation system that, while using high-resolution maps, only handles the basics and lacks advanced features such as traffic reporting and text-to-speech. Audi has a new system on the way, but the new Q5 model is the first car where we will see it. That new system will fix one of the worst features in the MMI, adding a joystick for easier map navigation, where in the S8 and other Audis you have to scroll around on an X and Y axis. We like the phone system in the S8, which pairs with a variety of phones and makes the contact list available on the car's LCD. The upcoming system will add voice recognition to the contact list, so you can dial by name, but that's not available in the current S8. Audi gets a little crazy with its music interface system. There's a custom port in the glove box and a bag full of cables so you can hook up a USB drive, iPod, mini-jack, or Mini-USB. We appreciate the choices, but it would be easier to just use a USB port that also works for iPods, like every other automaker. The iPod interface is excellent, letting you choose music by artist, album, genre, and playlist. These lenses, as Bang & Olufsen calls them, pop up from the dashboard when you turn the sound system on.We also had Sirius satellite radio and a six-CD changer in the glove box, the latter reading MP3 CDs. But as we noted above, you don't really want to use compressed music with this audio system, and even Sirius stations don't sound particularly good. The standard audio system uses 12 Bose speakers, but the Bang & Olufsen premium system has 14 speakers, all with beautiful metal grilles, and includes two high-range sound lenses that pop up from the dash when you start the car. The S8 offers several gadgets to help you drive and park. We mentioned the blind spot warning system and adaptive cruise control previously. Another cool tech feature is the lane departure warning, which surprised us by buzzing the wheel when we crossed a lane line. This system uses cameras on the sides of the car, but we found its lane line recognition algorithm oversensitive, buzzing the wheel even when there wasn't a painted line. The turn signal or a very deliberate turn will defeat the warning buzz. This parking system mixes a rearview camera display with a sonar graphic, giving you no excuse for hitting objects while parking.The parking system is nicely done, using turn guides on the rearview camera that show the car's path and distance to objects. The bumpers are also embedded with sonar detectors, and a graphic of the car shows how close objects are to the front and back. Under the hood The 5.2-liter V-10 in the 2009 Audi S8 uses all of Audi's tricks to generate 450 horsepower at 7,000rpm, including direct injection and variable valve adjustment for both the intake and exhaust. But this tech doesn't make the engine very fuel efficient, as its EPA mileage numbers are 13 mpg city and 19 mpg highway. During our testing period, we got 16.3 mpg with a significant amount of time driving on the freeway. Audi puts this same engine in a new version of the R8.To get moving, the engine makes 398 pound-feet of torque, that peak number coming on at 3,500rpm. With this big of a car, you don't feel a fast launch, but the speedometer usually shows greater speed than you expect, a testament to the car's sound-proofing and minimal vibration. The S8 also comes with an air suspension, adjustable for Comfort, Automatic, and Dynamic settings. We had it on Dynamic for much of our time with the car, which let us feel the road more than we would expect. Even in Comfort mode, the ride was harsher than in an A8, mostly because of the big, 20-inch wheels and low-profile rubber. You definitely feel the size of the S8 when cornering, but that air suspension keeps it surprisingly balanced. With this big of a car, it seems as if it should wallow just a bit in hard corners, but it stays flat and the speed-sensitive power steering offers good feedback. The front brake calipers, a little beefier than what you get on the A8, have an S8 logo.Keeping the car on the right line during cornering is its Quattro all-wheel-drive system, one of Audi's signature pieces of equipment. In the S8, the default torque distribution puts 40 percent of the torque to the front wheels and 60 percent to the rear. However, Audi has a new version of this system waiting in the wings, which we tested on the new A4. You might want to wait for a more significant update to the S8 if you are in the market. The six-speed automatic transmission has Drive, Sport, and Manual settings, the latter shiftable on the stick or with paddles. Manual shifts were reasonably fast, while the Sport mode merely seemed to keep the revs a little higher. There is no manual transmission available on the S8. In sum The 2009 Audi S8 starts at $96,200, and that base model already comes with a lot of gear, including the navigation and Bluetooth systems, plus the air suspension and Quattro. Bumping up the cost of our S8 was the Bang & Olufsen audio system, adding some spectacular sound for $6,300, and the $3,500 Technology package that brings adaptive cruise control, lane departure warning, and blind spot detection. Interior upgrades included $4,900 for stitched dashboard leather and $500 for the carbon fiber trim. A couple of other options and the $2,100 gas guzzler tax brought our total up to $115,775. One interesting option we didn't have is a solar roof, designed to keep a constant flow of cool air in the car thus reducing dependence on the air conditioning. There are only a few cars that go for this high end of luxury and performance. The Mercedes-Benz S-Class S63 AMG offers a little more power and similar cabin tech, but comes in some tens of thousands of dollars more in total price. For a greener image, the Lexus LS600h brings in a lot of comfort, along with good performance stats. In our ratings of the S8, we gave it near top marks for cabin tech, an area that's mainly let down by its archaic navigation system. Performance also earns an excellent rating, brought down a little by poor fuel economy and the car's tendency to hesitate a little before getting moving. And tech-wise, it actually falls behind the more humble A4, which features an updated Quattro system. Finally, its design is merely good, with a distinctive body styling that earns it points, but a cabin interface that leaves a lot to be desired.