The Good: The hybrid power train in the 2008 Mercury Mariner Hybrid, derived from the Toyota Synergy system, is the best around. Route guidance and features on its navigation system are good, as is the number of sources feeding into the audio system. The Bad: The Mariner Hybrid gets pricey for the small SUV market. The maps in the navigation system have poor resolution, and Bluetooth cell phone integration isn't available. The Bottom Line: The 2008 Mercury Mariner Hybrid has the practical configuration of a small SUV, along with the low emissions and good fuel economy of a hybrid. Its cabin electronics are up-to-date, although not extraordinary. Photo gallery:2008 Mercury Mariner HybridFord Motor Company finally realized that if you want to sell a high-tech car, you need to put high-tech gadgets in the cabin. In truth, the highest tech feature about the 2008 Mercury Mariner Hybrid is still the hybrid power train. But the newest model gets significantly improved cabin electronics over previous generations. The Mercury Mariner Hybrid and the Ford Escape Hybrid share the same platform, which includes body style, seating configuration, hybrid power train, and cabin electronics. The key difference between the two cars is that the Mercury presents a more refined style, sort of like the clothes you might wear out to a nice restaurant as compared to what you'll lounge around in on a Saturday. We've seen a lot of cars with a similar body style to the Mariner Hybrid recently, such as the Honda CR-V, the Mitsubishi Outlander, and the Suzuki Grand Vitara. All have a practical configuration, with four doors, easy access to the seats, and a rear cargo area that can be maximized by folding down the rear seats. The Mariner's design is chunky, giving the car a rugged look, although the grille suggests the refinement the Mercury brand is supposed to represent. The previous generation of Mariner\/Escapes had a tiny navigation screen and a navigation system running off of CDs. The new Mariner Hybrid gets a DVD-based navigation system with a proper-size screen, plus an in-dash six-disc changer. Its hybrid power train remains the same as in previous models, using a version of Toyota's Synergy system. This hybrid system is currently the best in the business. Test the tech: Zero-emission driving Because the hybrid system in the Mariner Hybrid can drive the car under electric power at low speeds, we staged a contest where CNET Car Tech editors Wayne Cunningham and Kevin Massy would see how long they each could keep the car going before the gas engine would start up. Each got their turn in the car, with a stopwatch keeping track of how long the car was under way. We staged the contest on the east side of San Francisco's Potrero Hill. We chose that location so each driver could take the car down the long hill of 19th Street in order to charge up the car's hybrid battery pack before the start of each run. During the run down the hill, each driver kept the car's regenerative brakes lightly applied, which sent electricity to the battery. A power-flow diagram on the car's LCD showed the level of battery charge. We used the long slope down 19th Street to charge the Mariner Hybrid's batteries.Kevin Massy went first, starting off at the bottom of the hill with a fully charged battery. Knowing hard acceleration would quickly cause the battery to drain and the engine to start up, he kept a very light foot on the gas pedal. The Mariner Hybrid uses both its gas engine and electric motor to jointly power the car when hard acceleration is needed. Kevin meandered around city blocks with little traffic, just off Third Street in an industrial part of the city. At 7 minutes and 38 seconds, the battery display showed empty and the gas engine kicked into life. Wayne Cunningham went next, running the Mariner Hybrid to the top of the hill, then down to recharge the battery pack. He drove a similar course as Kevin Massy, keeping to little trafficked industrial streets, with a light foot on the gas pedal. The car rolled along silently, using no gas and causing no emissions. But at 5 minutes and 1 second, the engine started up, running electricity back into the completely discharged battery. The battery hadn't gotten completely charged up for this second run, which partially explains the shorter running time. In the cabin With its clean-looking interior, the Mariner Hybrid accomplished its mission of being the upscale brother to the Ford Escape. The aluminum-look facing that covers the center stack contributes to the clean, modern look. And we were happy to see a regular-size navigation screen in the center stack after our experience with the previous generation of this car. Although we like the features on the navigation system, the map isn't the nicest we've seen.While the new DVD-based navigation system is a big improvement, it uses an ugly map with low resolution. We saw this same navigation\/stereo component in the Ford Expedition, although there is no voice-command function in the Mariner Hybrid. Besides its ugly map display, the navigation system is very functional. It has touch-screen operation, accurate route guidance, and many methods for entering a destination. We particularly like the ability to find the nearest freeway entrance or exit. You can also choose a destination from the map, but a couple of too-large onscreen buttons make this difficult. During route guidance, the navigation system reads out the names of streets, a nice high-end feature. When you start up the car, it also lets you know it has an Audiophile sound system. That description is a bit of a stretch, as the car only gets six speakers and a subwoofer, when you get the Premium package. But it is a reasonably good-sounding system and will do for most people. Just don't expect deep bass or a particularly rich sound. The channel guide for satellite radio makes it easy to find your favorite stations.The audio system is controlled through the LCD, with easy-to-use tabs for selecting sources. And this car features the whole range, including a six-disc MP3 capable changer, an auxiliary input neatly mounted at the bottom of the stack, and satellite radio. One gripe about the MP3 CD display--it uses large buttons that take up a lot of screen real estate, limiting the amount of track information that is shown. Also, we would have liked buttons on the steering wheel for controlling the audio system. A nice feature continued from previous Mariner Hybrids is the AC outlet located at the bottom of the stack, letting you plug in a laptop, a phone charger, or anything else. Bluetooth cell phone integration isn't available on the Mariner Hybrid, a feature we think appropriate for this class of car. Under the hood The hybrid system in the Mariner uses a 2.3-liter four-cylinder engine, with a 133 horsepower output, mated to a continuously variable transmission (CVT). The gas engine is augmented by a 70 kilowatt electric motor. A control module monitors the battery level, driver throttle input, and other car data to determine whether to run the car off the electric motor, or both the motor and the engine. It also decides when to use the engine to charge up the battery. Although the CVT doesn't lend itself to an exhilarating driving experience, the combination of the engine and motor provide enough power to get the car moving, with reasonable acceleration. When we first got behind the wheel, we found ourselves changing our driving demeanor radically, trying to optimize use of the hybrid system. We tended to accelerate lightly and frequently check the power-flow diagram to see the battery charge. There is also a gauge on the instrument cluster that shows when the battery is being charged and when the motor is assisting the engine. The tachometer needle also points to a wide, green band when the engine is off, at a stop or at low speeds. The extra power is noticeable when the engine turns off, but the transition is not uncomfortable. We got an estimated 45mpg in 15 minutes of city driving.Once we got over the novelty of hybrid driving, we resorted to our usual heavy foot for freeway entrances and beating the traffic off of a light. In this more normal style of driving, we were probably getting worse gas mileage, but the car was completely up to it. The car let us drive exactly how we wanted to. The EPA hasn't published mileage figures for the Mariner Hybrid yet, but we got 24.7mpg in driving that was biased toward the freeway. To get a better handle on city mileage, we snapped a picture of the car's mileage graph, which records the last 15 minutes of driving. Averaging out those numbers, we estimate about 45mpg for city driving in heavy traffic. The Mariner Hybrid isn't really meant for sport driving--it has some understeer and feels top heavy on the corners. We had a front-wheel-drive version, but all-wheel drive is available. We did end up taking the car over a particularly rough and windy mountain road, Las Tunitas, which winds from Highway 1, on the coast, to I-280. We were able to push the Mariner Hybrid pretty hard over this poorly paved road without feeling unsafe, so we would say the car handles moderately well. In sum We didn't have final pricing for our 2008 Mercury Mariner Hybrid, but expect to pay just less than $30,000 for one with a navigation and premium audio system. There are few choices for small hybrid SUVs, and we prefer the Mariner Hybrid over the Saturn Vue Green Line. Although the Vue is considerably cheaper, the Mariner's hybrid system is better. It offers greater boost from the motor and can drive the car under electric power. The navigation system and stereo, although not perfect, are also better than what we had in the Vue Green Line. And the Mariner Hybrid also does reasonably well when compared to other small SUVs, such as the CR-V, the Outlander, and the Grand Vitara. The Outlander and CR-V have better cabin gadgets, but won't match the Mariner Hybrid for fuel economy.