The Good: The beautiful 2008 Audi S5's engine delivers smooth power, while the Quattro all-wheel-drive system keeps the car on the road. The Bang & Olufsen audio system is in the top three car stereos we've heard, and the iPod integration complements it well. The Bad: There's a big price to pay for this kind of power, and it's in the form of lousy gas mileage. The Bottom Line: With its refined cabin tech, very nice performance, and beautiful design, the 2008 Audi S5 excels in most areas, only being dragged down by poor mileage and unambitious cabin tech. Photo gallery:2008 Audi S5We were impressed with the look of the Audi A5, when we saw it launched at the Geneva auto show earlier this year. But when the 2008 Audi S5 turned up on our car review schedule, we were pleased and surprised to get the S5 before the A5. As it turns out, Audi brought the S5 to market in the U.S., and as of this review, the A5 is not available. That's OK, though, as the S5 is not only beautiful, it is just about perfect. We loved driving this car, as it felt highly responsive while the engine gives a blast of power. Audi refined its navigation and Bluetooth systems, then upped the ante with a stellar Bang & Olufsen stereo system. At first, we found nothing to criticize about this car. But some issues emerged as we took it on our road tests. Test the tech: S5 Avenue During our review of the Mercedes-Benz GL320 CDI, we poked around in Northern California's wine country and found an excellent road for a sports car. At that time we were anticipating the arrival of the 2008 Audi S5 in a few weeks, so started referring to this road as S5 Avenue. With its long, sweeping turns and 35 mile run from Highway 101 to the coast, we knew it would be a blast to drive in the right kind of car. One fine Monday morning we jumped in the car and headed north. The car drove incredibly well on the freeway, letting us power up hills and around the slowpokes. At speed, the steering tightens up and offers more road feel than the low speed, parking lot setting. We also noticed an indicator on the small, high-resolution color LCD between the speedometer and tachometer that showed our current gear, and occasionally a second number, in green, suggesting we get into a higher gear for better fuel economy. This feature is useful because, even at its best, the S5 gets simply awful mileage. Our photo and video shoots with the S5 had already taken the tank down to half, so we stopped for a fill-up before we set out on S5 Avenue. We plot our course on a road we've renamed S5 Avenue.At the gas station, we set the navigation system to give us guidance to our starting point. We experienced a little frustration, as the system didn't let us search by name; instead we brought up the recreation areas category and had to scroll through page after page until we found our spot. We were previously able to do a search by name in the restaurant category, so we marked our frustration down to a confusing interface. On this part of the journey, we also took advantage of the car's stereo, being treated to some of the finest audio we've heard. But more on that later. Once on what we called S5 Avenue, we let the car run into its first corner, its gentle curve and the car's 354 horses calling for third gear. The tires made no complaint and we felt no slippage, as the Quattro all-wheel-drive distributed torque, keeping the car following where we pointed it. As we gathered confidence on this road, which included rises and downslopes replete with corners worthy of the corkscrew at Laguna Seca, we let the car run faster. On every corner we attacked, the car tracked perfectly, and there was no wheel slip or sliding. But as our speed picked up, we were surprised to find the car leaning heavily in the turns. G-forces were taking hold of the body, and the S5 just let it happen, apparently doing nothing to dampen the effect. We tried powering harder out of the turns to put the car on an even keel, but that only flattened it out a little. Later, we looked up the car's options and found that Audi's Magnetic Ride Suspension, which we used in the Audi TT Roadster and suspected would have counteracted the body roll, isn't an option for the S5. The approach to this turn is worthy of the run up to the corkscrew at Laguna Seca.On the second half of our S5 Avenue, body roll wasn't as much of a problem, as the turns tightened up considerably, putting us into second-gear territory. This stretch of road was dotted with speed-limiting chicanes in the form of areas where it narrowed down to one lane for both directions of traffic. Fortunately, there wasn't much traffic, except for the occasional tractor-trailer, another cue to be cautious on the many blind turns. The car performed well on these tighter turns, but we were relieved to finally hit the coast so we could pull over and stretch our cramping hands and clutch foot. Along the coast, we drove south, getting to experience some more of the car's excellent handling. And after a good four hours behind the wheel, we pulled back into the CNET garage, noticing the car's main flaw of having achieved just 16.3 mpg for this round trip of about 250 miles. In the cabin As a coupe, the 2008 Audi S5 doesn't offer the most spacious cabin. And while we liked the Tuscan Brown leather package and the wood inlays, the console and dash use some plastics that look cheap; not a great find in an expensive sports car. As for the cabin electronics, we've seen the Audi Multimedia Interface (MMI) and its navigation, Bluetooth, and stereo on past Audi models, but in the S5 everything seems a bit more refined. It looks as if Audi keeps fine-tuning these electronics to make them better, without making any radical changes. The MMI uses a large knob and buttons mounted on the console, the positioning previously reserved for bigger, more expensive Audis. As we saw in the new Audi A4 at the Frankfurt auto show this year, Audi is migrating the MMI controls to the console on even its lower end cars. One evolutionary step for the MMI we noticed in the similarly equipped Audi A6 earlier this year is that Audi color-coded the interface, making navigation screens blue, audio screens orange, and cell phone screens green, a nice visual cue. We were very pleased with the look of the navigation system's maps. They have a very high resolution and the system offers a long zoom range. The system worked fast and tracked the car well. When we were zooming along S5 Avenue, we frequently glanced at the map to anticipate upcoming turns. Entering addresses can be a little tedious with the rotary MMI dial, but the system quickly compiled predictive lists. The system doesn't have any extra features, such as live traffic or text to speech, but it handles the basics with excellence. iPod integration in the S5 is everything we would want, making an in-dash music server unnecessary.The stereo offers excellence all around. The audio system is built by Bang & Olufsen, a Danish stereo maker with a well-deserved reputation. Its partnership with Audi represents its first foray into the automotive market, a move that has been completely successful in the Audi S5. The car gets 14 speakers pumping out 500 watts into the cabin. Bass comes through with a palpable thump, and the highs are crystal clear. This system is in the same league as the THX system we heard in the Lincoln MKZ and the Mark Levinson system from the Lexus LS 460 L. The system responds very well to its bass, treble, and surround settings, letting you adjust the audio for your preferred music. The stereo doesn't lack sources, either. It has Sirius satellite radio and a six-disc changer that plays MP3 CDs. Finding your way through MP3\/CDs folders is easy with the MMI, and you can even choose music using the steering wheel controls and the display between the speedometer and tachmeter. Best of all, though, is the iPod integration. When we hooked up an iPod Nano to the cable in the glove box, we immediately had full access to our entire music library, with the MMI letting us choose music by artist, genre, album, track, and playlist. Although we would have liked an in-dash hard drive for music, the iPod integration makes up for that feature. This Bluetooth cell phone integration works well, giving you access to your cell phone book.The third part of this cabin trifecta is the Bluetooth cell phone integration, which is of the best we've seen. We paired a Samsung SGH-D807 to the S5, and almost immediately had full access to entries in our phonebook, along with the ability to dial individual numbers. The call quality was nice and clear on both ends, and the car's LCD shows the signal strength. There aren't many other tech treats in the cabin. We did have a rear-view camera, something Audi does better than any other car maker. This camera not only includes lines on the display to show how close you are to obstructions, but it also curves the lines when you turn the wheel, giving you an accurate guide for where your car will go. Under the hood While the cabin tech worked nicely, it was the driving experience in the 2008 Audi S5 that really won us over. The 354-horsepower, 4.2-liter V-8 gave very smooth power delivery, and combined with the car's six-speed manual transmission, made taking off from the line much too fun. Interestingly, with the clutch in you can't rev the car more than 4,000rpm, preventing high-rev clutch-dropping fast starts that would shorten the life of the transmission. While under way, we never got tired of the engine's growl as it wound up. Audi claims the car can get to 62 mph in 5.1 seconds. This direct injection 4.2-liter V-8 delivers excellent power and lousy mileage.Many cars have variable-assist power steering, but we found it very noticeable on the S5, with a very light wheel at slow speeds that quickly tightened up as our mph increased. We mentioned how the car handles above, the Quattro, which defaults to 40 percent torque in front and 60 percent in back, giving the car very accurate tracking with the steering. After our time with it, we can't imagine what you would have to do to get it to slide. But we were also surprised that an Audi S version would lean as much in the turns as the S5 did. Audi doesn't make its DSG transmission available on the S5, most likely because of the size of the engine. Instead, we had the six-speed manual. Audi calls it a short-throw, but we've had shorter. This six-speed is very precise, which we like, but did require us to push the stick a little further to get it into gear for what we would consider a short throw. But this criticism aside, we just really liked driving the S5, as all its driving gear felt extremely well-integrated. The car tracks very well with its Quattro system, but the car leaned quite a lot in the corners.But here comes the bad news. You will pay a gas-guzzler tax of $1,300 for the S5, because its EPA-rated economy is 14 mpg in the city and 21 mpg on the highway. During our time with it, we got the aforementioned 16.3 mpg for a long, highway-based drive, and we saw an average of 14.4 mpg overall. Emissions ratings for the S5 hadn't been published at the time of this review. In sum The 2008 Audi S5 comes in at a base price of $50,500, keeping Audi well-differentiated from its sibling, Volkswagen. We also had the navigation option, which included iPod integration, for $2,390, a $1,700 Technology package that brought in the rear-view camera, the Bang & Olufsen audio system for a very reasonable $850, and wood inlays for $500. Along with that ugly $1,300 gas-guzzler tax and a $775 destination charge, our S5 totaled $58,015. We like this car a lot, from its beautiful exterior, through its excellent cabin gadgets, and down to its exhilarating performance. It earned a top score for its design, as it does everything a coupe should do. Its cabin gadgets are excellent but don't earn it a perfect score in that category because it doesn't present anything truly cutting-edge, although the quality of the audio almost put it over the top. It would have also earned a perfect score in the performance category if it wasn't for the lousy gas mileage. The S5 also has little competition, as there are few high-performance luxury coupes with all-wheel-drive available. But next year look for the new BMW M3 and the Nissan GT-R to put it in its place.