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Active Fuel Management (formerly known as Displacement on Demand) is a trademarked name for the automobile variable displacement technology from General Motors. It allows a V6 or V8 engine to "turn off" half of the cylinders under light-load conditions to improve fuel economy. EPA tests show a 6% to 8% improvement in fuel economy, but real-world highway use promises even larger gains. This article or section does not cite its references or sources. ...
Variable displacement is an automobile engine technology that allows the engine displacement to change for improved fuel economy. ...
General Motors Corporation (NYSE: GM), also known as GM, is an American automobile maker with worldwide operations and brands including Buick, Cadillac, Chevrolet, GMC, Holden, Hummer, Opel, Pontiac, Saturn, Saab and Vauxhall. ...
The Ford Essex V6 engine A V6 is an internal combustion piston engine with six cylinders in a V configuration. ...
The Liberty V8 aircraft engine clearly shows the configuration A V8 engine is a V engine with eight cylinders. ...
Fuel efficiency, sometimes also referred to as fuel economy and commonly gas mileage in the United States, is a numeric measure often used to describe the amount of fuel consumed with regard to the distance travelled in a transportation vehicle, such as an automobile. ...
EPA redirects here. ...
GM's current Active Fuel Management technology uses a solenoid to deactivate the lifters on selected cylinders of a pushrod vee engine. For the ionic propulsion device, see Lifter (ionic propulsion device). ...
A pushrod engine or overhead valve (OHV) engine is a type of piston engine that places the camshaft below the pistons (usually beside and slightly above the crankshaft in a straight engine or directly above the crankshaft in the V of a V engine) and uses pushrods or rods to...
Background In the U.S., high-powered multi-cylinder internal combustion engines are perceived to be necessary to satisfy driver demands for quick acceleration, oversized vehicles and/or heavy towing capacity, but during daily use they are generally operated at power settings of less than 25%. For example, at freeway speeds, less than 40 hp (30 kW) are required to overcome aerodynamic drag, rolling friction, and to operate accessories such as air conditioning. Thus, a high-powered, large-displacement engine is highly inefficient and wasteful when being used for normal driving conditions- the vast majority of the time. High-capacity freeway interchange in Los Angeles, California. ...
An object falling through a gas or liquid experiences a force in direction opposite to its motion. ...
Rolling friction is the friction that occurs when an object (e. ...
Note: in the broadest sense, air conditioning can refer to any form of heating, ventilation, and air-conditioning. ...
In general a naturally aspirated gasoline engine provides maximum power when the engine throttle is held wide open. When less power is needed, the throttle is mostly closed. As such the engine has to work to simply draw air through the throttle. The work that's done is called a "pumping loss". If some of the cylinders could be switched off, however, less air would be required, and the throttle held wide open, thereby reducing pumping losses and increasing overall engine thermal efficiency. This is the motivation for cylinder deactivation. Gasoline engine (also referred to as petrol engine or Otto engine) invented at the end of the 19th century by German engineer Nikolaus Otto is a type of internal combustion engine which is often used for automobiles, aircraft, small mobile vehicles such as lawnmowers or motorcycles, and outboard motors for...
In order to deactivate a cylinder, the exhaust valve is prevented from opening after the power stroke and the exhaust gas charge is retained in the cylinder and compressed during the exhaust stroke. Following the exhaust stroke, the intake valve is prevented from opening. The exhaust gas in the cylinder is expanded and compressed over and over again and acts like a gas spring. As multiple cylinders are shut off at a time (cylinders 1, 4, 6 and 7 for a V8), the power required for compression of the exhaust gas in one cylinder is countered by the decompression of retained exhaust gas in another. When more power is called for, the exhaust valve is reactivated and the old exhaust gas expelled during the exhaust stroke. The intake valve is likewise reactivated and normal engine operation is resumed. The net effect of cylinder deactivation is an improvement in fuel economy and likewise a reduction in exhaust emissions. General Motors was the first to modify existing, production engines to enable cylinder deactivation. A power stroke is, in general, the stroke of a cyclic motor which generates force. ...
Exhaust gas is gas which occurs as a result of combustion of fuel such as gasoline/petrol, diesel or coal. ...
General Motors Corporation (NYSE: GM), also known as GM, is an American automobile maker with worldwide operations and brands including Buick, Cadillac, Chevrolet, GMC, Holden, Hummer, Opel, Pontiac, Saturn, Saab and Vauxhall. ...
Second generation The electronics side was improved greatly with the introductions of Electronic Throttle Control, electronically controlled transmissions, transient engine and transmission controls, engine emissions controls, and vastly increased computing power. A solenoid control valve assembly integrated into the engine valley cover contains solenoid valves that provide a pressurized oil signal to specially designed hydraulic roller lifters provided by Eaton Corp. and Delphi. These lifters disable and re-enable exhaust and intake valve operation to deactivate and reactivate engine cylinders. Unlike the first generation system, only half of the cylinders can be deactivated. It is notable that the second generation system uses engine oil to hydraulically modulate engine valve function. As a result, the system is dependent upon the quality of the oil in the engine. As anti-foaming agents in engine oil are depleted, air may become entrained or dissolve in the oil, delaying the timing of hydraulic control signals. Similarly engine oil viscosity and cleanliness is a factor. Use of the incorrect oil type, i.e. SAE 20W40 instead of SAE 5W20, or the failure to change engine oil at factory recommended intervals can also significantly impair system performance. A solenoid is a loop of wire, often wrapped around a metallic core, which produces a magnetic field when an electrical current is passed through it. ...
Motor oil is a type of liquid oil used for lubrication by various kinds of motors, especially internal combustion engines. ...
The pitch drop experiment at the University of Queensland. ...
The Society of Automotive Engineers is a professional organisation and standards body for the engineering of powered vehicles of all kinds - cars, trucks, boats, aircraft and more. ...
In 2001, GM showcased the 2002 Cadillac Cien concept car, which featured Northstar XV12 engine with Displacement on Demand. Later that year, GM debuted Opel Signum² concept car in Frankfurt Auto Show, which uses the global XV8 engine with displacement on demand. In 2003, GM unveiled the Cadillac Sixteen concept car at the Detroit Opera House, which featured an XV16 concept engine that can switch between 4, 8, and 16 cylinders. 2001: A Space Odyssey. ...
The 2002 Cadillac Cien at the Detroit Auto Show. ...
It has been suggested that this article or section be merged into Automotive design. ...
Northstar is Cadillacs name for its DOHC V8 engine. ...
The Opel Signum is an upper-midsize class car with a hatchback body, manufactured by General Motors in Germany. ...
Frankfurt Fairground The International Motor Show or Internationale Automobil-Ausstellung (IAA) is the worlds largest motor show. ...
2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ...
The Cadillac Sixteen was a prototype of a stylish and high performance car presented by Cadillac in 2003. ...
On April 8, 2003, General Motors announced this technology (now called Active Fuel Management) to be commercially available on 2005 GMC Envoy XL, Envoy XUV and Chevrolet TrailBlazer EXT using optional Vortec 5300 V8 engine. GM also planned to extend the technology on new High Value LZ8 V6 engine in some 2006 mid-size passenger cars. In both designs, half of the cylinders can be switched off under light loads. April 8 is the 98th day of the year in the Gregorian calendar (99th in leap years). ...
2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ...
The GMC Envoy is an SUV from the GMC marque of General Motors. ...
The Chevrolet TrailBlazer is a mid-size SUV from the Chevrolet division of General Motors. ...
Vortec is a trademarked name for a line of piston engines for General Motors trucks. ...
The High Value engine family from General Motors is a group of large pushrod V6 engines. ...
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