Mercedes-Benz reveals SLS E-Cell performance data

AppId is over the quota
AppId is over the quota

The electric version of the Mercedes-Benz SLS uses four electric motors mounted near the wheels and a central-mounted battery pack.

Mercedes-Benz has lifted the veil of secrecy on the plug-in-electric propulsion system of its upcoming SLS E-Cell, first revealed in concept form at the 2009 Frankfurt auto show.

Set to go into limited production in early 2013, the zero-emission version of the German carmaker's signature gullwing coupe is set to rival a raft of new high-priced electric or hybrid supercars due out in the not-too-distant future, including the Audi E-tron, the BMW i8, the Jaguar C-X75 and the Porsche 918.

The car is undergoing development at Mercedes-Benz's performance-car AMG unit and its British-based sister company, AMG High Performance Powertrains--the company behind Mercedes' latest 2.4-liter V6 Formula One race engine.

The SLS E-Cell eschews the naturally aspirated 6.2-liter V8 gasoline engine of its standard sibling for a quartet of synchronous electric motors--one mounted at each corner of its carbon-fiber-and-aluminum body structure and driving all four wheels--for a combined output of 526 hp and a heady 649 lb-ft of torque.

The motors, supplied by Bosch, are capable of reaching a rotational speed of up to 12,000 rpm and drive through two separate fixed-gear transmissions--one mounted on each axle and both featuring torque vectoring to provide selective distribution of drive forces to the wheels possessing the most traction. AMG claims that design ensures only minimal electronic-stability-program intervention, even on wet and/or slippery road surfaces. By comparison, the standard SLS uses a six-speed dual clutch gearbox and rear-wheel drive.

Energy for the SLS E-Cell's electric motors is provided by a 400-volt lithium-ion battery pack mounted within the space usually reserved for the SLS's transmission tunnel and fuel tank behind the driver and passenger seats. It consists of 864 individual cells provided by Korean battery specialist SK Innovations. They are arranged in 12 individual modules, each consisting of 72 cells and providing an overall energy density of 48 kilowatt-hours and a maximum load of 480 kilowatts, which AMG boss Ola Kaellenius describes as “an absolute best in the automotive sector.”

By mounting the four electric motors low at each corner and the battery wholly within the wheelbase, AMG claims to have achieved a weight distribution of 46:54 front-to-rear and a center of gravity nearly 1 inch lower than that of the gasoline-powered SLS coupe.

In addition to plug-in recharging, the SLS E-Cell uses a multistage variable kinetic-energy-recuperation system (KERS) operated via steering-wheel-mounted paddles. The recharging technology was first developed by AMG High Performance Powertrains for the KERS system used on McLaren's Mercedes-Benz-engined car during the 2009 F1 season and subsequently improved for use on this year's Mercedes-Benz-engined F1 race cars.

Unlike the standard SLS coupe, which uses an all-aluminum body, the SLS E-Cell employs a more complex carbon-fiber-reinforced plastic (CFRP) and aluminum structure revealed at last year's Frankfurt motor show. Its key element is a transmission tunnel fashioned out of CFRP, which is structurally integrated into the existing aluminum structure.

The stiff, high-strength CFRP component helps reduce weight while creating a zero-intrusion cell that protects the batteries from damage in the event of a crash. The use of carbon fiber means that the SLS AMG E-Cell's transmission tunnel is about 30 percent lighter than the transmission tunnel in a standard SLS, which goes some way to offsetting the extra weight of the batteries.

Mercedes-Benz has not revealed a weight figure for the production version of the SLS E-Cell just yet, but its high-tech propulsion system is claimed to provide it with a 0-to-62-mph time of 4.0 seconds, just 0.2 second more than the standard SLS coupe, and a top speed that is likely to be limited to 155 mph.

Get more car news, reviews and opinion every day: Sign up to have the Autoweek Daily Drive delivered right to your inbox.

Autoweek loves passionate comments and debate, but remember that you're part of a diverse community. Above all: be respectful. Critique statements, not people; talk about the automotive world, but skip the political rhetoric, hate speech, and obscenities. While we can't read every post, this site is moderated and Autoweek will remove comments as we see fit. Questions? Read our Terms of Use or email moderator@autoweek.com.

View the original article here

Mercedes-Benz E 63 AMG car review

Mercedes’ uber-sensible E-Class big car now has a discreet-but-bonkers alter ego in the shape of the E 63 AMG.

The ‘63’ bit relates to its 6.3 litre V8 engine, which is electronically limited to 155 mph, but will fling this hefty car to 60 in 4.5 seconds, which is fast motorcycle territory.

Each engine is assembled by a single technician in a facility that resembles an operating theatre, and is spectacularly powerful, producing 525bhp. Despite having a lot of moving parts, this motor can be revved to 7,200rpm, and will switch painlessly from unobtrusive, easy-going town speed trundling to scenery-blurring mayhem, accompanied by an exotic, expensive sounding mechanical roar.

It does all this with great smoothness, but without a turbocharger, and is about 12 per cent more fuel efficient than the car it replaces (a combined 31mpg is claimed, but you’d probably get a lot less pressing on). Economy is helped by clever petrol metering systems and an alternator that recoups the energy that would otherwise be lost when the car’s huge brakes are applied.

The AMG’s efficiency is also helped by its seven-speed sports transmission. This works like a conventional, two pedal automatic, but uses a clutch rather than a torque converter – the latter would sap more energy. It can be manually controlled by a neat, short throw transmission tunnel lever, which employs fly-by-wire technology (expect to see this on other future Mercede s) or steering wheel paddles, and is both fast and slick.

The driver can select four modes, from relatively easy going to rapid fire staccato shifts, and the system has an entertaining party trick of sometimes automatically ‘blipping’ the engine as it changes down the gears, so that the motor and transmission speeds match, making for smoother, faster changes.

To help this big car get round corners, AMG has developed a new front axle, which uses steel springs and electronically controlled dampers. Its rear is air sprung. The result is decent ride quality for a hefty saloon with low profile tyres, but almost roll-free cornering.

The specially developed rack-and-pinion steering is speed sensitive and faster than the standard E-Class system, and accurate without being skittish or nervous. The result is a forgiving, confidence-inspiring car which is easy to drive on normal roads, although you’re always conscious of its size.

Given that most versions of the E-Class are destined to waft executives from meetings, or spend their lives as taxis, it comes as little surprise that both the boot and interior are big. With acres of dark leather and plastics, the cabin feels slightly dour, but the fit, finish and quality of the materials used all seemed first class. This is important, because the Mercedes came unstuck a while back with a well publicised fall off in build quality.

The instruments and controls are all painless to use, which is good, given that this is an exotic car with a lot of equipment, and front seat occupants can be entertained by electronically adjustable seat backrest wings, which can be made to hold their occupants in place when this car is being hurled through bends.

The AMG’s slightly odd-looking front lights automatically adjust to prevailing conditions, and the car comes with the expected shed load of safety kit, from traction control systems to things that warn the driver that he or she is letting the car wander about. There’s even a system to detect if a driver is getting drowsy, and the car will shriek and beep if it thinks things are going awry.

Anyone who considers M Power versions of BMW’s 5 Series a bit too brash might well gravitate towards this go-faster Mercedes, which is a sober looking thing adorned with some low key visual tweaks, including deeper bumper sections, discreet badging and enormous alloy wheels shod with big, low profile tyres.

They give what is otherwise a slightly anonymous big saloon an attractive visual presence.

As this was written Mercedes hadn’t fixed a price, but was talking about ‘under £70,000.’ That’s a lot of money for any car, but the 63 AMG’s buyers will be paying for something a bit special, and with UK sales likely to be under 100 units a year, quite rare too.

Model tested: Mercedes-Benz E 63 AMG
Date tested: June
Road tester: Martin Gurdon