American historian Will Durant once paraphrased Aristotle in this clever way: "We are what we repeatedly do. Excellence, then, is not an act but a habit." We wouldn't be surprised if Mercedes uses this as a motivational poster for its engineers. Year after year, the Mercedes Benz E-Class exemplifies excellence, regularly ranking at the top of our midsize luxury car list. It's a benchmark for refined ride quality, confident handling, meticulous craftsmanship, clever innovation and sophisticated comfort.

With the 2013 Mercedes-Benz E-Class, excellence also includes variety. There are sedan, coupe, convertible and wagon body styles, plus engines that range from fuel sippers to outlandish horsepower monsters. The E-Class lineup alone would otherwise represent the full model portfolio from some other luxury brands.

For 2013, the lineup expands with the new Mercedes-Benz E400 Hybrid, which will be available later in the model year. Similar to the S-Class hybrid, the E400 hybrid pairs its 3.5-liter V6 with a small electric motor and a lithium-ion battery pack. The improvement in fuel economy isn't substantial, but the wallop of extra torque from the electric motor should appeal to those with a penchant for acceleration rather than conservation.

It's true that some E-Class rivals offer sportier, more dynamic handling, but we contend that for most buyers in this segment, luxury trumps performance. Among sedans, we rank the 2013 Audi A6, 2013 BMW 5 Series and 2012 Jaguar XF as very close 2nd-place finishers. For coupe, convertible and high-performance variants, Audi's A5, S5 and RS 5 and BMW's M3 and M5 deserve a look. But for consistent excellence, it's hard to beat the 2013 Mercedes-Benz E-Class.

The 2013 Mercedes-Benz E-Class is available in five-passenger sedan, four-passenger coupe, four-passenger convertible (Cabriolet) and seven-passenger wagon body styles. Each is further broken down into different trims that correspond with its engine. The sedan is available in E350, E350 Bluetec, E400 Hybrid, E550 4Matic and E63 AMG variants. The cabriolet is offered in E350 and E550 (with a coupe-only E350 4Matic) trim levels, while the E-Class wagon is available in E350 4Matic and E63 AMG guises. (4Matic refers to the all-wheel-drive system.)

The E350, E350 Bluetec and E400 Hybrid sedans are similarly equipped with 17-inch wheels, automatic headlights, LED running lights, a sunroof, automatic wipers, cruise control, dual-zone automatic climate control, 10-way power front seats with four-way lumbar adjustment and memory functions, MB-Tex premium vinyl upholstery, a power tilt-and-telescoping steering wheel, ambient lighting, auto-dimming inside and driver-side mirrors, the COMAND electronics interface, Bluetooth, the Mercedes' mbrace telematics system and an eight-speaker sound system with a six-CD changer and an auxiliary audio jack. The E350 sedan distills further into Luxury and Sport sub-trims, which vary in suspension tuning, styling, interior trim and wheel design.

The E350 wagon gets standard all-wheel drive, a power liftgate, a rearview camera and a rear-facing third-row seat. The E350 coupe gets heated front sport seats, leather upholstery, a 60/40 split-folding backseat and a console-mounted transmission lever with paddle shifters. The E350 Cabriolet gets a power-folding roof, a rear center pass-through and the AirCap pop-up air deflector.

Every E550 adds bigger brakes, 18-inch wheels and leather upholstery (optional on the E350). The E550 4Matic sedan comes with standard all-wheel drive and the Sport sub-trim items, while the coupe gets a sport-tuned suspension and a sport body kit.

The optional Premium 1 package adds a navigation system, a rearview camera, heated seats, a power rear window shade for the sedan and coupe, satellite radio, a 14-speaker Harman Kardon surround-sound audio system and an iPod interface. E550 buyers also get ventilated front seats with this package. The Cabriolet version of this package includes the AirScarf neck-warming system.

The Premium 2 package adds adaptive bi-xenon headlights with washers and automatic high beams, a power trunk lid and keyless ignition/entry. The Lane Tracking package adds blind-spot detection and a lane departure warning/keeping system. The Driver Assistance package adds adaptive cruise control and advanced versions of the Lane Tracking items.

Stand-alone options on the sedan and wagon include front and rear parking sensors (also offered on coupe and Cabriolet), split-folding rear seats, heated and ventilated front seats (E350), a panoramic sunroof, enhanced front seats with adjustable bolsters, a heated steering wheel, an infrared night vision warning system and a rear-seat entertainment system. Most sedans and wagons can also upgrade to a 14-speaker Bang & Olufsen surround-sound system.

The range-topping E63 AMG includes most of the E550's equipment plus a larger V8, various AMG-engineered and -tuned components (transmission, suspension, steering, brakes, exhaust), headlight washers, a sport steering wheel, sport seats with adjustable bolsters, unique interior and exterior trim, and the premium sound system with satellite radio and an iPod interface. The sedan gets a power rear sunshade and a split-folding rear seat, while the wagon offers a panoramic roof.

AMG models can opt for the Premium 1, Premium 2, Lane Tracking and Driver Assistance packages along with most of the stand-alone features, as well as a limited-slip differential, 19-inch forged alloy wheels and carbon-fiber trim. Finally, the AMG Performance package adds power, more aggressive suspension tuning (sedan only), a sportier steering wheel, a higher top speed, red brake calipers and a carbon-fiber engine cover.

The 2013 Mercedes-Benz E350 models come with a 3.5-liter V6 that produces 302 horsepower and 273 pound-feet of torque. A seven-speed automatic transmission is standard on every E-Class, as is rear-wheel drive on all but the wagon. The wagon comes with all-wheel drive (4Matic), which is also available for the sedan.

In Edmunds performance testing, an E350 wagon accelerated from zero to 60 mph in 6.5 seconds, which is average for the class. We expect the rear-wheel-drive variants to be quicker still. The EPA estimates fuel economy for a rear-drive E350 sedan at 20 mpg city/30 mpg highway and 23 mpg in combined driving. Other models drop by 1 or 2 mpg lower in each driving cycle.

The E400 Hybrid uses the same 3.5-liter V6 for the E350, along with a seven-speed automatic transmission and an electric motor that adds 27 hp and 207 lb-ft of torque. Mercedes-Benz hasn't yet announced the E400 Hybrid's total combined output. This hybrid is offered as a rear-wheel-drive sedan only, and Mercedes estimates fuel economy at 24/31 mpg.

The E350 Bluetec features a 3.0-liter V6 turbodiesel that uses a liquid treatment to reduce particulates in its exhaust emissions. It produces a modest 210 hp but a very robust 400 lb-ft of torque. Rear-wheel drive is standard. In Edmunds testing, an E350 Bluetec reached 60 mph in 7.7 seconds. Although slow for the class, scant few competitors can claim fuel economy estimates of 21/32/25 mpg.

E550 models get a twin-turbo 4.7-liter V8 that produces 402 hp and 443 lb-ft of torque. Rear-wheel drive is standard on the coupe and Cabriolet, while the sedan gets standard 4Matic. Mercedes says the sedan can dash to 60 mph in a quick 5.2 seconds, while the coupe and Cabriolet can do it in 5 seconds flat or faster. EPA-estimated fuel economy is 16/26/20 mpg for the sedan, while the convertible drops about 1 mpg and the coupe does about 1 mpg better.

The E63 AMG gets a twin-turbo 5.5-liter V8 that cranks out 518 hp and 516 lb-ft of torque. The AMG Performance package bumps this to 550 and 590, respectively. Rear-wheel drive and the AMG seven-speed automated manual transmission are standard. Mercedes expects it to reach 60 mph in about 4.2 seconds. Fuel economy is an EPA-estimated 16/24/19 mpg for the sedan and 15/23/18 mpg for the wagon.

Standard safety features for the 2013 Mercedes-Benz E-Class include antilock disc brakes, stability and traction control, front side airbags, front pelvic airbags, side curtain airbags and a driver knee airbag. Also standard is the updated Mercedes-Benz mbrace emergency telematics service, a drowsy driver alert and pre-collision automatic braking. The Cabriolet features automatic rollover hoops.

The Lane Tracking package adds blind-spot detection and a lane departure warning/keeping system. The Driver Assistance package adds adaptive cruise control and more advanced versions of the Lane Tracking items that can take evasive action should the driver fail to do so. Rear side airbags are a stand-alone option.

In Edmunds brake testing, an E350 sedan with all-season tires came to a stop from 60 mph in 121 feet, while an E350 4Matic wagon with summer tires stopped in 109 feet -- both average distances for cars equipped with those tire types.

The 2013 Mercedes-Benz E-Class strikes a brilliant balance between ride quality and handling ability. Within its segment, the E is the most adaptable, rewarding and confident car for the widest variety of surfaces and situations. It's not the most athletic pick, but nevertheless offers highly tactile steering, strong engines and a chassis that inspires confidence. Regardless of body style or engine, the Mercedes-Benz E-Class is a special luxury car to drive.

The Mercedes-Benz E63 AMG is even more remarkable, able to seat five in comfort and sprint from zero to 60 mph in 4.2 seconds. Myriad upgrades -- suspension, steering, brakes, wheels, tires and transmission -- make for a serious performance machine. If you're simply looking for a go-fast Benz without the more hard-core bits, the E550's twin-turbo V8 offers wicked acceleration like the AMG E-Class models of only a few years ago.

The cabin of the 2013 Mercedes-Benz E-Class is meant to evoke classic themes from past models, combining angular architecture, first-rate materials and a decidedly austere look, especially when adorned in monotone color schemes and dark wood trim. The general design is the same regardless of body style, except for the available three-spoke sport steering wheel and electric gear selector (column-mounted in the sedan and wagon; console-mounted in the coupe, convertible and AMG).

All E-Class models come with the COMAND electronics interface, which combines a large display screen, a control knob and dash-mounted buttons. Although it requires a bit of a learning curve, we generally prefer it to rival systems from Audi or BMW. Also included is the updated mbrace telematics system, offering smartphone integration and Web-based apps that include remote controls, driver monitoring and emergency services.

Every E-Class is relatively comfortable and spacious for their respective segments. The seats are firm, but offer impressive comfort and support for the long haul. The two-door and AMG models feature snug sport seats that keep you in place through quick, sharp turns. The sedan's backseat is quite spacious, matching the BMW 5 Series as the most welcoming rear quarters in the midsize luxury class. With the wagon, you get a generous 57 cubic feet of maximum cargo capacity and a rear-facing third-row seat.

The convertible offers comfortable seating for four, although rear passengers nearing 6 feet tall may feel a bit hemmed in. The Cabriolet is also one of the most serene convertibles around thanks to the AirCap system, which minimizes air turbulence to a trickle even at high speed. The coupe's rear-seat legroom, meanwhile, rates about the same as in most luxury two-doors, but headroom is limited.