Engine displacement is defined as the total volume of air/fuel mixture an engine can draw in during one complete engine cycle; it is normally stated in cubic inches, cubic centimeters, or litres. In a piston engine, this is the volume that is swept as the pistons are moved from... Displacement on Demand is an A small variety of cars, the most popular kind of automobile. An automobile is a wheeled vehicle that carries its own engine. Different types of automobile include cars, buses, vans and trucks, with cars being the most popular by far. Older terms include horseless carriage and motor car, with motor... automobile Variable displacement is an automobile engine technology that allows the engine displacement to change for improved fuel economy. Many automobile manufacturers have adopted this technology as of 2005, but it is not a new concept. Most variable displacement systems work by turning off a bank of cylinders in a V... variable displacement technology from GM redirects here. For other uses, see GM (disambiguation). General Motors Corporation (NYSE: GM), also known as GM, is a United States-based automobile maker with worldwide operations and brands including Buick, Cadillac, Chevrolet, Daewoo, GMC, Holden, Hummer, Oldsmobile, Opel, Pontiac, Saturn, Saab, and Vauxhall. Chevrolet and GMC divisions produce... General Motors. It allows a The Ford Essex V6 engine A V6 is an internal combustion piston engine with six cylinders in a V configuration. It is the second most common engine configuration in modern cars after the straight-4; it shares with that engine a compactness very suited to the popular front wheel drive... V6 or The Liberty V8 aircraft engine clearly shows the configuration :See also V8 (beverage) A V8 engine is a V engine with eight cylinders. Overview The V8 is a very common configuration for large automobile engines. V8 engines are rarely less than 3 litres in displacement and in automobile use have... V8 engine to "turn off" one bank of cylinders under light-load conditions to improve 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. The measure is usually expressed in... fuel economy. The mission of the United States Environmental Protection Agency (EPA) is to protect human health and to safeguard the natural environment: air, water, and land. The EPA began operation on December 2, 1970. The EPA is not a cabinet agency, but its administrator is normally given cabinet rank. Stephen L... EPA tests show a 6% to 8% improvement in fuel economy, but real-world highway use promises even larger gains.

GM's current Displacement on Demand technology uses a solenoid to deactivate the For the ionic propulsion device, see Lifter (ionic propulsion device). Piston engines In piston engines, a lifter, cam follower, or tappet is a device that actuates a poppet valve through rocker arms and pushrods. Cam followers are needed to transfer the radial forces caused by the rotating cams on the... lifters on one bank of a A pushrod or overhead valve ( OHV) type piston engine places the camshaft below the pistons and uses pushrods or rods to actuate lifters or tappets above the cylinder head to actuate the valves. This contrasts with an overhead cam (OHC) design which places the camshafts above the cylinder head and... pushrod vee engine.

Background

High power multi-cylinder gasoline engines are typically necessary to satisfy driver demands for quick acceleration and/or heavy towing capacity, but during daily use they are generally operated at power settings of less than 25%. For example, at A typical freeway with an interchange in the foreground Rush hour on the Harbor Freeway in downtown Los Angeles A typical rural freeway (Interstate 5 in the Central Valley of California). Stack interchanges often feature soaring ramps with stunning views of nearby scenery. For the rapper, see Freeway (rapper). A... freeway speeds, less than 40 hp (30 kW) are required to overcome aerodynamic The word drag has several meanings: In physics, drag is a combination of aerodynamic or hydrodynamic forces. In computing, to drag is to click the mouse button and hold it down while moving the mouse. In music, to drag is to play slower than the indicated tempo. In drumming, a... drag, Rolling friction is the friction that occurs when an object (e.g a wheel or tire) rolls. It is much smaller than sliding friction except for special cases like ice skating. It is caused by the deformation of the wheel or tire or the deformation of the ground. It depends... rolling friction, and to operate accessories such as Note: in the broadest sense, air conditioning can refer to any form of heating, ventilation, and air-conditioning. This article is specifically about the use of refrigeration for this purpose. The first album of the pop group Curved Air was Airconditioning An air conditioner (often abbreviated to AC in the... air conditioning.

In general a naturally aspirated Gasoline (or petrol) engine 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 boats. The most common engine of this type is a four stroke cycle internal combustion engine that burns gasoline (in... 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 magically 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.

There is in fact a way to switch off cylinders, and it's not magic. Following the A power stroke is, in general, the stroke of a cyclic motor which generates force. It is used in describing mechanical engines and molecular motors such as ATP synthase. Many types of motors can be simply describes by first, intake stroke(intake of fuel, e.g. gasoline, ATP, etc.) then... power stroke, the exhaust valve is prevented from opening and the Exhaust gas is gas which occurs as a result of combustion of fuel such as gasoline/petrol or diesel. It is discharged to atmosphere through an exhaust pipe. Although much of it is harmless carbon dioxide, part of it is noxious or toxic substances, such as carbon monoxide (CO), hydrocarbons... 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, 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. GM redirects here. For other uses, see GM (disambiguation). General Motors Corporation (NYSE: GM), also known as GM, is a United States-based automobile maker with worldwide operations and brands including Buick, Cadillac, Chevrolet, Daewoo, GMC, Holden, Hummer, Oldsmobile, Opel, Pontiac, Saturn, Saab, and Vauxhall. Chevrolet and GMC divisions produce... General Motors was the first to modify existing, production engines to enable cylinder deactivation.

First Generation

GM's first use of Displacement on Demand was in 1981 is a common year starting on Thursday. Events January-February January - Sarawak Chamber found January 1 - Greece enters the EEC January 1 - Palau becomes self-governing January 4 - Sheffield police arrests Peter Sutcliffe, the Yorkshire Ripper January 10 Townsville International Airport opens (aus) January 16 - Protestant gunmen shoot and... 1981 on the Cadillac, when used alone, can refer to: Cadillac, Michigan Cadillac, General Motors luxury car brand. Antoine Laumet de La Mothe, sieur de Cadillac (1658-1730), for whom the above are named Cadillac, a commune in the Gironde département, in France Cadillac, a Spanish pop group This is a disambiguation... Cadillac Cadillac was the first automobile maker to mass produce a V8 engine. The company has produced eight generations of V8s since 1914, and today is the only General Motors division to retain its own V8 design. L_Head The Type 51 was the first Cadillac V8. Introduced in 1914, it was... V8-6-4 engine. GM's engine controller, based on engine load, signalled electro-mechanical An actuator is the mechanism by which an agent acts upon an environment. The agent can be either an artificial intelligence agent or any other autonomous being (human, other animal, etc) a mechanism that puts something into automatic action is called an actuator. Some examples of actuators of these various... actuators designed, developed, and manufactured by Eaton Corp. to engage or disengage rocker arms to permit or prevent engine valve operation, thereby deactivating cylinders. The system was capable of operation with 4, 6, or 8 cylinders.

GM's design used the existing manual, cable throttle control, a new Fuel injection is a technology used in internal combustion engines to mix the fuel with air prior to combustion. As in a traditional carburetor, fuel is converted to a fine spray and mixed with air. However, where a traditional carburetor forces the incoming air through a venturi to pull the... throttle-body fuel injection system, a conventional An automatic transmission is an automobile gearbox that can change gear ratios automatically as the car moves, thus freeing the driver from having to shift gears United States since the 1950s have had automatic transmissions. This has, however, not been the case in Europe and much of the rest of... automatic transmission, and a new engine controller. Upon deactivation of engine cylinders, the system was dependent upon the driver to depress the accelerator to maintain vehicle speed. Perhaps the most troubling issue with this system was that it employed a throttle-body fuel injection system, i.e. electronic The carburetor (or carburettor, carb for short) is a device which mixes air and fuel for an internal_combustion engine. Carburetors are still found in small engines and in older or specialized automobiles such as those designed for stock car racing. However, most cars built since the early 1980s use fuel... carburetor. It continuously supplied fuel to all cylinders. When a cylinder was deactivated, fuel could accumulate in the intake port until the intake valve was reactivated. At this point the accumulated fuel was dumped into the cylinder causing an over-rich mixture, poor Combustion or burning is an exothermic reaction between a substance and a gas to release heat. Combustion normally occurs in oxygen (often in the form of gaseous O2) to form oxides, However, combustion can also take place in other gases like chlorine. The products of such reactions usually include water... combustion, and erratic engine output torque, ultimately resulting in drive train jerk and poor driveability. The automatic transmission used a conventional A torque converter is a hydraulic device prevalent in automatic transmissions and marine propulsion systems, such as diesel powered ships, where two or more engines are driving a common shaft. It consists of a toroidal chamber containing two elements, a centrifugal pump (forming the front part of the housing and... torque converter and was not equipped to dampen engine output torque variations which occurred during cylinder deactivation and reactivation. The engine controller was barely capable of processing sensor signals and valve activation/deactivation signals in real-time in a system that demands micro-second accuracy. Deactivation of a single cylinder must begin during the power stroke, i.e. during the exhaust cam's base circle. The controller must signal the rocker arm pedestal-mounted actuator to mechanically disengage the rocker arm that opens the exhaust valve. Similarly the deactivated cylinder's intake rocker arm must also be disengaged. Upon reactivation, the controller must signal the appropriate exhaust and intake valve rocker arm actuators at the correct times. Unfortunately, the engine controller was unable to properly control the timing of deactivation and reactivation signals at high engine speeds, and as a result the stored exhaust gas charge could backflow into the intake manifold causing engine backfire. All of these multiple issues, in addition to innovative, but unreliably implemented technologies applied to carburetion and engine control contributed to erratic engine behavior when deactivating and reactivating engine cylinders. Because of its unreliability and poor performance, many of these vehicles had been converted to use 8 cylinders all the time. Cadillac V8-6-4 only lasted one year, but continued on Cadillac A limousine (or limo) is a long luxury car, traditionally black in color. Limousines are often driven by chauffeurs. A black Lincoln stretch limousine at a car show in Bristol, England While some limousines are owned by wealthy individuals, many are owned by governments to transport senior politicians, by large... limousines until 1984.

Cars using the Cadillac 4-6-8 engine include:

• The Cadillac Deville is Cadillacs largest and most luxurious car model. It is sometimes converted for limousine use. Partly to justify its high price, it tends to feature leading-edge automotive technology. It was one of the first cars to feature airbags, Night-vision technology, XM Satellite Radio, OnStar... Cadillac DeVille
• The Cadillac Brougham was the last rear wheel drive Cadillac in the 1990s. It used the super-long 121.5 in wheelbase D-body platform, and used 5.0 L and 5.7 L Chevrolet small-block V8 engines. The Brougham was retired in 1992 as the... Cadillac Brougham
• 1973 Eldorado convertible The Eldorado name was part of the Cadillac line from 1953 to 2003. The name refers to a legendary city of gold and was reputedly suggested by a secretary at Cadillacs home office, who considered it the only name rich enough for such an opulent model... Cadillac Eldorado
• The Seville, introduced in 1975, was Cadillacs answer to the fuel crunch of the early 1970s, and the rising popularity of luxury imports in the USA from Europe, such as Mercedes_Benz and BMW. At one time, Cadillac toyed with the idea of bringing back the LaSalle moniker for its... Cadillac Seville (optional)

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 In engineering, a solenoid is a mechanical device that converts energy into linear motion. Solenoids can be constructed to use electricity, compressed air (pneumatic solenoids), or pressurized fluids (hydraulic solenoids). An electrical solenoid is a form of electromagnet. In its simplest construction it consists of a number of turns of... 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 Motor oil is a type of liquid oil used for lubrication by various kinds of motors, especially internal combustion engines. Other benefits from using motor oil include cooling by carrying heat away from moving engine parts and often include cleaning and corrosion inhibition in internal combustion engines. The major fraction... engine oil to hydraulicly 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 is a measure of the resistance of a fluid to deformation under shear stress. It is commonly perceived as thickness, or resistance to pouring. Viscosity describes a fluids internal resistance to flow and may be thought of as a measure of fluid friction. Thus, methanol is thin, having... viscosity and cleanliness is a factor. Use of the incorrect oil type, i.e. SAE may refer to: Sigma Alpha Epsilon Society of Automotive Engineers SAE Institute In the United Kingdom Stamped addressed envelope. This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. If an article link referred you here, you might want... SAE 20W40 instead of SAE 5W20, or the failure to change engine oil at factory recommended intervals can also significantly impair system performance.

In 2001 is a common year starting on Monday of the Gregorian calendar. By strict interpretation of the Gregorian Calendar, 2001 is also the first year of the 21st century and the 3rd millenium. Popular culture, however, often views the year 2000 as holding this distinction. 2001 is also the year... 2001, GM showcased the 2002 Cadillac Cien A concept car is a car prototype made to showcase a new vehicles styling, technology, and overall design before production. They are often shown at motor shows to gauge customer reaction to new and radical designs which may or may not have a chance of being produced. General Motors... concept car, which featured Northstar is Cadillacs name for its DOHC V8 engine. The engine was introduced in 1992 in the Cadillac Allante and continues to be used in the Cadillac STS, Cadillac SRX, and Cadillac XLR. It was sold exclusively by Cadillac for over a decade before being introduced in the Pontiac... Northstar XV12 engine with Displacement on Demand. Later that year, GM debuted Opel Signum² concept car in Frankfurt International Motor Show, which uses the global XV8 engine with displacement on demand. In 2003 is a common year starting on Wednesday of the Gregorian calendar, and also: The International Year of Freshwater The European Disability Year Events January January 1 - Luíz Inácio Lula Da Silva becomes the 37th President of Brazil. Pascal Couchepin becomes President of the Confederation 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.

On April 8 is the 98th day of the year in the Gregorian calendar (99th in leap years). There are 267 days remaining in the year. Events 217 Roman emperor Caracalla is assassinated (and succeeded) by his Praetorian Guard prefect, Marcus Opellius Macrinus 1730 - Shearith Israel, the first synagogue in New... April 8, 2003 is a common year starting on Wednesday of the Gregorian calendar, and also: The International Year of Freshwater The European Disability Year Events January January 1 - Luíz Inácio Lula Da Silva becomes the 37th President of Brazil. Pascal Couchepin becomes President of the Confederation in... 2003, General Motors announced displacement on demand technology to be commercially available on 2005 The GMC Envoy is a luxury SUV from the GMC marque of General Motors. There have been two different vehicles to bear this model name, the 1998-2000 Envoy, and the 2002-present Envoy. 1998 For 1998, the Envoy was a luxury trim line of the GMC Jimmy SUV, itself... GMC Envoy XL, Envoy XUV and The Chevrolet TrailBlazer (and similar Buick Rainier, GMC Envoy, Oldsmobile Bravada, Isuzu Ascender, and the upcoming Saab 9-7X) is a SUV from General Motors. Introduced in 2002, the TrailBlazer won the North American Truck of the Year award. The name is taken from the concept of blazing a trail... Chevrolet TrailBlazer EXT using optional Vortec is General Motors trademarked name for a line of piston engines for trucks. The name first appeared in 1986 on a 4.6 liter V6 but now adorns a wide range of different engines. Modern Vortec engines are named for their displacement There are a number of Vortec engines... Vortec 5300 V8 engine. GM also planned to extend the technology on new The High Value engine family from General Motors is a group of large pushrod V6 engines. They use the same 60° vee bank as the older 60° V6 family, but the new 99 mm bore required expanding the bore spacing by 1.5 mm. These engines feature optional... 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.

See also

• Variable displacement is an automobile engine technology that allows the engine displacement to change for improved fuel economy. Many automobile manufacturers have adopted this technology as of 2005, but it is not a new concept. Most variable displacement systems work by turning off a bank of cylinders in a V... Variable displacement

Links

• GM Powertrain's Displacement on Demand whitepaper (http://www.gm.com/automotive/gmpowertrain/tech/pdf/DoD.pdf)
• XV8 concept engine (http://www.acarplace.com/brands/gm/xv8-engine.html)
• XV12 concept engine (http://www.caddyinfo.com/xv12.htm)
• XV16 concept engine (http://www.cadillac.com/cadillacjsp/models/feature.jsp?model=sixteen)
• Opel Signum² press release (http://media.gm.com/news/releases/010912opelsignum.html)
• GM press release (http://www.prdomain.com/companies/g/gm/news_releases/200305may/pr_gm_nr_20030508.htm)