2010 Mercedes-Benz S-Class Base S400 Hybrid 4dr Sedan Base (A7) Transmission: 7-Speed Automatic

Primary among changes for 2010 is the addition of the S400 Hybrid model.The first production hybrid with a lithium-ion battery the S400 maintains S-Class performance while significantly increasing fuel economy and lowering emissions without any of the typical hybrid compromises: Even when equipped as the S550 the S400 is the least expensive S-Class and has the same large trunk space.

Another noteworthy item, optional on any S-Class is Splitview.This arrangement allows the driver and passenger to see a different image at the same time on the central dashboard screen.The driver may want to check maps and traffic while the passenger watches a movie rather than gridlock, and with Splitview both can.

Other 2010 changes are smaller in scale and include things like front and rear lighting changes to make more use of LEDs.No detail escapes attention on the S-Class, and the same LED strip beneath the headlights (except base S400) shows white as a parking light and amber as a turn signal.

At nearly 300 horsepower, the S400 is the least-powerful S-Class, yet capable of an electronically limited 130 mph.An S550 will reach 60 mph 1.8 seconds earlier in ideal conditions and offers all-wheel drive for less-ideal conditions, the S600 and S63 AMG almost a second quicker still (4.5 seconds), and the S65 AMG in 4.2 seconds.They're more powerful than the numbers suggest, as even approaching its 186-mph limiter the S65 is still pulling like a freight train.

These cars handle remarkably well for big luxury sedans, composed, responsive and stable at any speed.The Airmatic air suspension system has both automatic and manual controls for ride height and firmness, transmissions bring multiple operating modes, and the braking system bred on the Autobahn's have massive reserves at more pedestrian American speeds.

Inside, you are surrounded by wood, leather and finishes befitting an expensive car.Separate overhead lit vanity mirrors, ambient cabin lighting and multiple air vents characterize the base model's rear seat.Technophiles may revel in the best night vision system on the market, cruise control that will maintain following distance up to 125 mph or stop the car automatically, a smart man-machine interface, and seats that will massage, cool and self-inflate under lateral loads.

The Mercedes S-Class competes with the Audi A8L, BMW 7 Series, and to a lesser extent the Lexus LS.The Mercedes S63 AMG matches up to Alpina BMW and the smaller but sportier-handling Maserati Quattroporte, Porsche Panamera and Aston-Martin Rapide, while the S65 makes a less-ostentatious (and faster accelerating) alternative to Bentley's Flying Spur Speed.

All S-Class models include leather upholstery, dual-zone climate control, walnut trim, navigation system with voice recognition and Zagat guide, heated 14-way power front seats with lumbar, heated power mirrors, 600-watt harman/kardon 15-speaker, 6CD, Logic 7 surround sound system with weather band and satellite radio, front/rear illuminated vanity mirrors, air suspension with ride height and damping control, bi-Xenon headlamps, and full power accessories.Most come with a moonroof and 18-inch wheels as standard.

S400 uses a 3.5-liter Atkinson-cycle gasoline V6 and 120-volt lithium-ion battery-powered electric motor for 295 net hp (EPA 19/26) and a seven-speed automatic transmission.Options are substantial: Premium 1 ($1,380) includes heated/ventilated front seats, power trunk closer, adaptive high-beam assistant, active-curve headlights, LED running lights; Premium 2 ($4,950) includes Premium 1 plus rear camera, Parktronic guidance, Keyless-Go, Drive Dynamic multi-contour/massage front seats); Driver Assist ($2,900) includes Distronic Plus with PreSafe, blind spot assist; Sport ($5,800) adds AMG bodywork and 19-inch wheels; Sport Plus One ($6,550) features special bodywork, 20-inch wheels; Rear Seat package ($2,900) includes left-right climate control and 8-way power heated and ventilated seats; Rear Entertainment ($2,450) features dual-source dual-screen with remotes, video inputs and DVD drive); leather upgrade ($1,350); 19-inch wheels ($1,250); 20-inch wheels ($2,000); wood/leather steering wheel ($580); power rear side window shades ($740); heated steering wheel ($480); illuminated door sills, four ($950); Splitview ($700); Panorama roof ($1,070); Night View with pedestrian detection ($1,740).

S550 has a 5.5-liter 382-hp V8 and seven-speed automatic (EPA 15/23) and is available with 4MATIC ($3,000).An S550 gets the S400's Premium 1 package as standard, along with the wood/leather steering wheel.Options include the Premium 2, Driver Assist, Sport/Sport Plus One, Rear Seat, and Rear Entertainment packages, all the S400 standalone options, and Active Body Control active suspension ($4,020).

S63 AMG uses a 518-hp 6.2-liter V8 and seven-speed automatic transmission (EPA 11/18).Both Premium packages are standard, as are AMG-grade Active Body Control suspension, brakes, 20-inch wheels and bodywork.Options are the Driver Assist, Rear Seat and Rear Entertainment packages, Splitview, Night View, and an AMG Performance package with a higher limited speed and carbon-fiber/piano black trim ($7,180).

S600 comes with a 510-hp twin-turbo 5.5-liter V12 (EPA 11/17), five-speed automatic, wider rear wheels and most equipment standard.Primary options are limited to Split View and 19- or 20-inch wheels.

S65 AMG comes with a 604-hp twin-turbo 6-liter V12 (EPA 11/17), five-speed automatic and AMG-enhanced chassis like the S63.For $200,000 virtually everything but Splitview and Diamond White paint is included.

Safety features on every S-Class include eight airbags, electronic stability control and PreSafe which will close the roof and windows and reposition the seat and its pneumatic lumbar for an impending collision.Fully equipped models use radar to stop the car automatically from up to 125 mph if the driver fails to pay attention and can alert the driver to unsafe lane changes.Night View offers a black-and-white TV-picture-like image of the road and people ahead in the central dashboard area used for the speedometer (which becomes a bar-graph along the bottom edge while ancillary gauges remain as normal).

LED lights have become more prominent with most versions sporting white daytime running lights in the lower bumper, standing lights and parking lights that switch to amber for front signals.As parking lights a strip of LEDs below the headlamps and three vertically on the side illuminate, but as standing lights (as you might use when parallel-parked on a dark lane) only the three vertical lights and corresponding rear LEDs glow, so you could leave them on overnight without affecting the battery.New tail lights that get rid of the body-colored strips within are attention-getting LED as well; V12 models get adaptive brake lights that blink rapidly during heavy braking.

The S-Class design has discernible fender flares front and rear, classic grille more laid back, and a generally flowing shape not unlike the ultra-lux sister-brand Maybach.These lines pay off in minimal noise and aero drag, high-speed stability, and an air of exclusivity afforded by the rear doors more than four feet long and the chrome strip framing the side glass.AMG models get quad oval tail pipes, a more aggressive look and air management with visual mass added to the lower bodywork, deeper grille and larger diameter wheels available with the Sport package on non-AMG models.

To keep weight down, the hood, door skins, and front fenders are constructed of aluminum alloys, as are the engine, transmission and most major suspension components, and the trunk lid is made of composite material.Much of the rest is high-strength steel.An S-Class is one of the best places to be in a big crash.

Details are well executed, be they the gaps between body panels, the transition from glass to roof to glass again, mirrors that fold narrower than the widest part of the car or keyless entry that works effectively for all doors and the trunk.All doors are self-sealing so you needn't slam them, positive door stops keep them at any position you open them to, there are no sharp edges inside or out, and the paintwork is very well finished.

Apart from badges the S400 and S550 look similar, while the S600 gets V12 badges for the front fenders and dual double-square tailpipes.S63 fender badges read 6.3 AMG in homage to past Mercedes cars of 6.3-liter fame (never mind the S63 engine is actually 6.2 liters).The S65 fender merely has a V12 BITURBO that should make everyone else think twice before offering to run for pink slips.

At least seven wheel styles are offered across the entire S-Class, from 18 to 20 inches in diameter.Potential buyers should be aware that larger diameter wheels generally impart a less-smooth ride, don't shrug off potholes as well, and often have limitations regarding tire chains or winter tires for inclement climes.We recommend the 18-inch wheels.

Heated, 14-way powered front seats offer three memory settings each side, wide ranges of adjustment including seat cushion length and will frequently adjust headrest height automatically, which like many controls, you can manually override if you wish.Metaphoric window switches that look like miniature replications of the seats are mounted on the doors to ensure they are easy to reach and understand.On cars with power rear seats the driver may switch to control the seat behind him.Meanwhile, the right rear passenger (the boss position) may control the right front seat for additional legroom.

Drive Dynamic front seats offer ventilation, four varieties of massage, further adjustments for cushion and back sides, lumbar and shoulders.Also, in what amounts to a sport seat with the comfort of a fine armchair, these seats can inflate side bolsters relevant to cornering load to hold you in place without being confining.After using it, we aren't quite sold on this feature as we found it distracting when cornering, but it can be turned off; we like the massage feature.Each seat is independently controlled and linked to the memory system.

Visibility is very good for the driver, with a sloping hood, reasonable pillars, parking sensors at both ends, rear camera, bi-Xenon headlamps, fine-line defrosters, eight heated windshield washer jets, and rear headrests that drop out of sight at touch of a driver's button.

The three-belt rear seat is huge and offers four AC vents, separate cabin and reading lamps, overhead lit vanity mirrors, and the same adjustable-color-and-intensity ambient lighting as the front hidden below the woodwork strips.Behind the center armrest is another storage area and power side shades are optional.

If your clients or kids are worth it a rear-seat upgrade package adds left/right rear climate control, plus heated and ventilated power-adjustable outboard seats and headrests.This setup provides the utmost in comfort while maintaining five-passenger capability.The entertainment package adds a height adjustable screen with video inputs behind each front headrest, video inputs and a DVD drive under the center rear seat, dual wireless headphones and an individual remote for each screen and the car's main audio system.

Instruments provide standard data, the central speedometer a screen image; everything from navigation and radio to driver assists and mpg can be called up here via the steering wheel thumb buttons, and on AMG cars, additional engine info or a lap timer stopwatch.With Night View engaged the screen shows an image of the view ahead with pedestrians highlighted, with speed along the bottom and warning lights superimposed around the periphery of the image.Its central line of sight location and crisp imagery make this the best system of its type.

The navigation screen, which can be angled toward driver or passenger and brightness adjusted separately from the instruments, is top center and well shaded.Every operation done through the central controller shows here.

A new option for 2010 and unique to the American market is Splitview.This potentially marriage-saving device lets the driver see one full-size image (map, radio, seat control) while the passenger sees another (a movie with headphones or map if they're navigating) simultaneously on the single central screen.Slide across the rear seat or walk behind the car and you'll be asking how did they do that.

Controls are extensive.Major driving controls are on the steering column, with a PRND shift stalk and upshift paddle on the right, downshift by the left hand (the paddles are close to the wheel with little finger space between).On the left are stalks for cruise control, wheel tilt/telescope, and a busy one with signals/main beams/wipers/washers on it.Suspension, parking and illumination controls are on the dash betwixt gauges and nav screen.The eight-position light switch has off and automatic modes but even in off the headlights were often on in daylight, even after we consulted the six pages of owner's manual regarding the lights.

Climate controls are arrayed across the center dash with true dual-zone operation, not merely independent temperatures.The system also gives a choice of how airflow is layered and distributed through the cabin, lest you prefer room temperature or a constant direct flow of air over you.

Mercedes-Benz dubs their control system COMAND and uses a round knob that rotates and moves in three dimensions, a mouse-shaped palm-rest that hides a 10-key pad within and four quick-access buttons across the front.Through a series of quick-to-master menus and scrolls it controls hundreds of things, and while you can rotate the COMAND knob to change radio stations you can also use the keypad to punch the number directly.The system is competitive with Audi's MMI, BMW's newest iteration of iDrive and Lexus mouse controller.

Finishes are superb and mix contemporary like piano-black and ribbed brushed metal surfaces with more traditional wood and chrome.Some of those high-gloss surfaces glare in the sun but those are single points because there are very few flat surfaces.For details note how the center console opens from either side, the chrome lip on the strip of wood sweeping across the dash and doors, how the woodwork bends around the COMAND controls and console, and how window switches also handle the shades.You know there has to be plastic in here somewhere but you never notice it, and the giveaway point on most cars, the pillar between the doors, is carpeted about a third of the way up and then covered in headliner material.All S-Class have leather though there are different grades available, and more money usually brings an Alcantara headliner as well.

S-Class comes with a 600-watt, 15-speaker harman/kardon Logic 7 surround sound system with a 6-DVD changer and memory card in the dash (auxiliary inputs are out of sight in the glovebox and run through the COMAND screen).An analog clock rides center dash, on AMG models it is from watchmaker IWC Schaffhausen Ingenieur.

Cabin storage includes a sizable pocket in each door, smaller pockets within the front door armrests, center console cupholders and bins, and a moderate-size glovebox.The 20-cubic-foot trunk is ideally square-angled and tall, and therefore holds more cases and bags than many vehicles with greater listed capacity.Some models have smaller bins underfloor above the spare tire, and it's worth noting that the S400 has the same trunk as the non-hybrid S-Classes.

The S400 Hybrid does not meet some definitions of hybrid since it will not propel itself on electric-power alone.However, it does increase fuel mileage more than 25 percent in the city and to a rated 26 on the highway (we recorded 21.7 around town and 27.6 on the highway) with no downside or price premium; the battery is in the engine compartment and the S400 weighs only 19 pounds more than S550.With a combined power output of 295 hp and broad torque its acceleration betters most hybrids but an S550 is quicker, yet an S550 invokes traction control trying to use all its power from a standing start anyway.

Five characteristics segregate S400 from S550: The S400 Hybrid makes a different noise, not rougher or louder, merely different.It often switches off automatically when stopped to save fuel so the tachometer swings to zero; taking your foot off the brake or touching the gas pedal restarts it, and it makes this transition smoother than any hybrid we can think of, including pricier V8s.In places where you are going very slowly, as you might creeping into a tight parking spot, the idle stop may be more active than you like so just resting your big toe on the gas pedal to keep the gas engine running will smooth things nicely.The brake pedal has more of an on/off switch feel to it because that's a lot of what it does, but if you hit it the S400 will stop in short drama-free order.Finally, powertrain/battery status is added to the various display options.

Ride quality is superb, S-Class air suspension combining smoothness with complete control and utter stability as you waft along faster than you think.We found it duly goes where it's pointed and if you think yourself getting into an off-ramp a bit too fast you'll be impressed by what this 4,500-pound mass can do even before any electronics come into play to save you from your own poor driving habits.The suspension can be raised at slow speeds for excessive speed bumps or driveway angles, lowers at higher speeds for stability and economy, and can be firmed up in Sport mode if you prefer quicker reactions to pillow-gentle manners.

Steering inputs are fluid, linear, predictable and surprisingly crisp for such a long wheelbase; on some models a quick turn puts a touch of brake to a rear wheel to help encourage the turn but there is no artificial feel introduced when it happens.Brakes are easily modulated and seem endless in their ability to retard harder as you further depress the pedal.

An S550 behaves essentially the same way except for more significant thrust by virtue of its 382 horses and 391 lb-ft of torque, nearly 300 of which is available at just 1000 rpm.S-Class cars start in second gear to save fuel (unless you've chosen Sport or Manual modes), but even when starting in second gear we found the S550 has considerable urge.The 4MATIC model gets going more easily in poor conditions.

Active Body Control (ABC) adds another element to suspension control by mechanically countering the acts of physics.As the steering wheel is rotated to make a bend the car automatically alters suspension to remain flatter.If you've ever watched a motor race where the driver swerves back and forth to warm or clean tires but the car appears to lean very little, ABC gives the same effect to a much heavier, taller, softer riding car.BMW's 7 Series offer active suspension as well but they lack the linear, more organic feel of the S-Class.

The S600, with a twin-turbo V12 engine, whirs and hums rather than starts and runs, with a fluidity matched only by more-expensive twelve-cylinder cars.With 510 hp and a prodigious 612 lb-ft of torque (at just 1800 rpm) the S600 gets a five-speed automatic because the seven-speed automatic can't handle it.The S600 will run 0-60 in less than five seconds with four people on board as long as you can find traction.S600 uses 18-inch wheels like lesser S-Class but they're wider in back to help cope with the power.We found the S600 has such ample reserves of power at any speed that the gas pedal should be treated as such.

The S63 AMG is rated at 518 hp, but it is a different breed than the S600.With a hand-built 6.2-liter V8 that burbles and bristles like a refined muscle-car, it revs to 7200 rpm.With a mere 465 lb-ft of torque, the S63 uses an AMG-modified version of the seven-speed automatic transmission.It matches the S600 for speed but has crisper, racier response, although the seven-speed didn't seem any quicker shifting to us than older AMG gearboxes.Along with the biggest V8 from Germany come massive brakes, AMG-calibrated ABC suspension, 20-inch wheels and ultra-low profile tires, and every component is designed to maintain a torrid pace.The S63 is not the fastest S-Class but it is the most driver-oriented and the most sporting.

The S65 AMG is a wolf in sheep's clothing that marries the leather-and-suede luxury of an S600 with the sporting chassis of an S63 to a 6-liter twin-turbo V12 and SpeedShift five-speed automatic.It generates 604 horsepower and a staggering 738 lb-ft of torque at 2000 rpm as smoothly as a jet engine, making your head the nail, the headrest a center-punch and your right foot the hammer.With more torque than any diesel pickup and twice the horsepower of a typical sport sedan an S65 with traction control off can spin tires through 70 mph and is electronically limited to three-miles-per-minute top speed.It will accelerate ferociously from 60 mph to 120 faster than most cars will from stop to 60, yet is easily managed if you don't switch too many things off and we found it downright docile when driven moderately.Effortless is a wholly appropriate descriptor here.

Every S-Class driver has a quiet cabin to work with virtually free of wind noise to freeway speeds and normal-volume conversations (with your driving instructor) can be maintained at 130 mph.Road noise increases nominally with larger wheels and still won't be heard above a talk-radio program, and engine noise is greater in the AMG models but either will cruise in subdued tones.

New Car Test Drive correspondent G.R.Whale filed this report from Los Angeles after his test drive of the S-Class models.