Tag Archives: internal combustion engine

Coolest, Classiest Electric? Mercedes SLS AMG eDrive

While at the Nurburgring for a first-ever drive of the coming 2010 Mercedes-Benz SLS AMG Gullwing, I also had the opportunity to sit down with Volker Mornhinweg as the AMG CEO showed-off some highlights of his next new vehicular baby: an all-electric version of the Gullwing.

The eDrive version, says Mornhinweg, “will use exactly the same white body as the gasoline-powered car. There’s plenty of room in the existing structure to put electric motors at each wheel and batteries on the floor, ahead of the firewall, and just aft of the seats. The only change is up front, where we’ll have to change the front axle to a pushrod suspension to accommodate the motors.”

Mornhinweg is clearly excited about the eDrive project. “This is not a concept car. The SLS eDrive will be on the road perhaps as early as 2013—certainly by 2015 at the latest.” As such, it’ll be a continuation of AMG’s goal to reduce fleet-average C02 emissions by 30 percent by 2012. “The challenge for the future is to deliver superb performance, but also social acceptance,” says Mornhinweg. “The internal-combustion engine is going to be around for a long, long time, but to improve its efficiency we’ll be using more and more direct injection, downsizing displacement while adding turbocharging, incorporating stop/start systems, and more. You’ll see more four-cylinder engines in the future, too.”

The AMG boss sees myriad benefits to the SLS eDrive. “The SLS’s lightweight aluminum body and structure will help to offset the heavy batteries we’ll need for maximum performance.” Zero to 60 mph, Mornhinweg adds, will take around 4 seconds flat, with a top speed of about 125 mph. Because each wheel will be driven by its own motor, electric four-wheel drive is inherently part of the design. “By tailoring the software that guides the motors, we can also do exciting things like torque vectoring and dynamic stability control,” Mornhinweg says.

The three modular high-voltage batteries in the SLS eDrive will be lithium ion—powering the four electric motors through two transmissions (one per axle). Peak output is equivalent to 526 horsepower (392 kW) and nearly 650 pound-feet of torque—the eDrive should be a formidable player in stoplight Grands Prix. Range won’t be outstanding—only about 95 to 110 miles—but the batteries will recharge to 80 percent of capacity in around five to six hours (plug in when you reach work if you have a long commute home). Plugging-in overnight will deliver a full charge. (Regen brakes, of course, will help to freshen the batteries when driving.)

Mornhinweg is confident that no major hurdles exist in bringing the eDrive to market. And he emphasizes that the eDrive will not replace the SLS’s 6.2-liter gasoline V-8; the two versions will coexist. “Our biggest challenge,” he notes, ”will be adding the emotion that’s so crucial to the enjoyment of a sports car. For instance, with electric drive there’s no vroom vroom during downshifts, which is a sound every enthusiast driver enjoys. So we’re experimenting with various ways simulate the experience using the two transmissions and the electric motors. I’m confident, though, that when we’re finished we’ll have what many enthusiasts will find a very desirable car.”

Which is to say, with its speed, those show-stopping gullwing doors, and that zero-emissions powertrain underneath, the SLS AMG eDrive promises to offer driving sex without the guilt.

Source : blogs.motortrend.com/6563064/editorial/coolest-classiest-electric-mercedes-sls-amg-edrive/index.html


A hydrogen car is an automobile which uses hydrogen as its primary source of power for locomotion. These cars generally use the hydrogen in one of two methods: combustion or fuel-cell conversion. In combustion, the hydrogen is “burned” in engines in fundamentally the same method as traditional gasoline cars. In fuel-cell conversion, the hydrogen is turned into electricity through fuel cells which then powers electric motors. With either method, the only byproduct from the spent hydrogen is water.

A small number of prototype hydrogen cars currently exist, and a significant amount of research is underway to make the technology more viable. The common internal combustion engine, usually fueled with gasoline (petrol) or diesel liquids, can be converted to run on gaseous hydrogen. However, the most efficient use of hydrogen involves the use of fuel cells and electric motors instead of a traditional engine. Hydrogen reacts with oxygen inside the fuel cells, which produces electricity to power the motors. One primary area of research is hydrogen storage, to try to increase the range of hydrogen vehicles while reducing the weight, energy consumption, and complexity of the storage systems. Two primary methods of storage are metal hydrides and compression. Some believe that hydrogen cars will never be economically viable and that the emphasis on this technology is a diversion from the development and popularization of more efficient hybrid cars and other alternative technologies.

High speed cars, buses, motorcycles, bicycles, submarines, and space rockets already run on hydrogen, in various forms. There is even a working toy model car that runs on solar power, using a reversible fuel cell to store energy in the form of hydrogen and oxygen gas. It can then convert the fuel back into water to release the solar energy.

BMW’s Clean Energy internal combustion hydrogen car has more power and is faster than hydrogen fuel cell electric cars. A limited series production of the 7 Series Saloon was announced as commencing at the end of 2006. A BMW hydrogen prototype (H2R) using the driveline of this model broke the speed record for hydrogen cars at 300 km/h (186 mi/h), making automotive history. Mazda has developed Wankel engines to burn hydrogen. The Wankel uses a rotary principle of operation, so the hydrogen burns in a different part of the engine from the intake. This reduces pre-detonation, a problem with hydrogen fueled piston engines.

However the major car companies like DaimlerChrysler and General Motors Corp, are investing in the slower, weaker, but more efficient hydrogen fuel cells instead. Hydrogen fuel cells run directly on hydrogen fuel, or on hydrogen produced in the vehicle from reforming methane or gasoline (this from petroleum), or natural ethanol, while hydrogen internal-combustion cars run on hydrogen only.


Flexible fuel

A flexible-fuel vehicle or dual-fuel vehicle is an automobile or truck (lorry) that can typically alternate between two sources of fuel. A common example is a vehicle that can accept gasoline mixed with varying levels of ethanol (gasohol). Some cars carry a natural gas tank and one can switch from gasoline to gas.

North American vehicles from approximately 1980 onward can run on 10% ethanol/90% gasoline (e.g., E10) with no modifications. Prior to 1980, many cars imported into the United States contained rubber, aluminium, and other materials that were generally non-compatible with any ethanol in their fuel delivery systems, and these cars experienced problems when E10 was first introduced. American made cars from the late 1970s onward can run on E10 with no modifications. E10 fuel is widely available. Going beyond 10% ethanol generally requires special engineering.

In the United States, many flexible-fuel vehicles can accept up to 85% ethanol (E85). The fuel mixture is automatically detected by one or more sensors, and once detected, the ECU tunes the timing of spark plugs and fuel injectors so that the fuel will burn cleanly in the vehicle’s internal combustion engine. Originally, sensors in both the fuel-line and in the exhaust system were used for flexible fuel vehicles. In recent years, manufacturers have instead opted to use only sensors in the exhaust manifold, before the catalytic converter, and to eliminate the fuel inline sensor. As E85 is more corrosive, special fuel lines are also required. Some manufacturers also required a different motor oil be used, but even this requirement is now dropped for all but one manufacturer.