Tachometer showing red lines above 14,000 rpm.

Redline refers to the maximum engine speed at which an internal combustion engine or traction motor and its components are designed to operate without causing damage to the components themselves or other parts of the engine. The redline of an engine depends on various factors such as stroke, mass of the components, displacement, composition of components, and balance of components. Image File history File links Metadata Size of this preview: 800 × 533 pixelsFull resolution (3888 × 2592 pixel, file size: 3. ... Image File history File links Metadata Size of this preview: 800 × 533 pixelsFull resolution (3888 × 2592 pixel, file size: 3. ... This article does not cite any references or sources. ... This article does not cite any references or sources. ... Traction motor typically refers to those motors that are used to power the driving wheels of a railroad locomotive, electrical multi-unit train (such as a subway or light rail vehicle train), or a tram. ... A stroke is a single action of certain engines. ... One complete cycle of a four cylinder, four stroke engine. ...

Engines with short strokes can handle higher rpm because there is less force in reciprocating motion. Lighter components can increase the redline as well, since they have less inertia and decrease forces present in the engine. Components of a typical, four stroke cycle, DOHC piston engine. ... Inertia is the property of an object to remain at constant velocity unless acted upon by an outside force. ...

An engine's redline is described by the manufacturer, who usually determines it by stress-testing the engine.^{[citation needed]}

Redlines vary anywhere from a few hundred revolutions per minute (rpm) (in very large engines such as those in trains and generators) to more than ten thousand rpm (in smaller, usually high-performance engines such as motorcycles and sports cars with pistonless rotary engines). Diesel engines normally have lower redlines than comparatively-sized gasoline engines, largely because of fuel-atomization limitations. Gasoline automobile engines typically will have a redline at around 5500 to 7000 rpm. The VTEC engine in the '00-'03 Honda S2000 had the highest production car redline at 9000 rpm. The Renesis rotary engine in the current Mazda RX-8 also has a redline of 9000 rpm, although such engines can run at much higher speeds, it is necessary to protect the ancillary components and gearbox. Motorcycle engines can have even higher redlines because of their comparatively lower reciprocating mass. For example, the Yamaha YZF-R6 has a redline of about 16200 rpm. Higher yet is the redline of a modern Formula One car. Regulations limit the maximum engine rotation to 19,000 rpm, but during the 2006 season, engine speeds reached over 20,000 rpm on the Cosworth engine. For other uses, see Revolutions per minute (disambiguation). ... A pistonless rotary engine is an internal combustion engine that does not use pistons in the way a reciprocating engine does, but instead uses one or more rotors, sometimes called rotary pistons. ... This article does not cite any references or sources. ... 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... VTEC is an acronym for Variable Valve Timing and lift Electronic Control. ... “S2000” redirects here. ... 12A redirects here. ... The Mazda RX-8 is a sports car manufactured by Mazda Motor Corporation. ... Yamahas YZF-R6 is a 600cc sport bike. ... Formula One - Wikipedia, the free encyclopedia /**/ @import /skins-1. ... Cosworth Logo Cosworth is an automotive engineering company founded in London in 1958 specialising in engines for automobile racing. ...

The actual term redline comes from the red bars that are displayed on tachometers in cars starting at the rpm that denotes the redline for the specific engine. Operating an engine in this area is known as redlining. Straying into this area usually does not mean instant engine failure, but may increase the chances of damaging the engine. Tachometer showing engine RPM (revolutions per minute), and a redline from 6000 and 7000 RPM. A tachometer measures the speed of rotation of a shaft or disk (from Greek: tachos = speed, metron = measure), as in a motor or other machine. ...

Most modern cars have computer systems that prevent the engine from straying too far into the redline by cutting fuel flow to the fuel injectors/carburetor or by disabling the ignition system until the engine drops to a safer operating speed. Most Electronic Control Units (ECUs) of automatic transmission cars will upshift before the engine hits the redline even with maximum acceleration (an automatic transmission sport car's ECU will allow the engine to go nearer the redline or hit the redline before upshifting). If manual override is used, the engine will go past redline for a brief amount of time before the ECU will auto-upshift. When the car is in top gear and the engine is in redline (due to high speed), the ECU will cut fuel to the engine, forcing it to decelerate until the engine begins operating below the redline at which point it will release fuel back to the engine, allowing it to speed operate once again. // Fuel injection is a means of metering fuel into an internal combustion engine. ... Bendix-Technico (Stromberg) 1-barrel downdraft carburetor model BXUV-3, with nomenclature The carburetor, carburettor, or carburetter (see spelling differences), also called carb (in North America) or carbie (chiefly in Australia) for short, is a device that blends air and fuel for an internal combustion engine. ... In automotive electronics, an electronic control unit (ECU) is an embedded microcomputer that controls one or more of the electrical subsystems in a vehicle. ... An automatic transmission is an automobile gearbox that can change gear ratios automatically as the vehicle moves, thus freeing the driver from having to shift gears manually. ... Acceleration is the time rate of change of velocity, and at any point on a velocity-time graph, it is given by the slope of the tangent to that point basicly. ... A Manual Override is a proceedure where an otherwise automatic system is taken under manual control, usually from computer control. ...

However, even with these electronic protection systems, a car is not prevented from redlining through inadvertent gear engagement. If a driver accidentally selects a lower gear when trying to shift up, the engine will be forced to rapidly rev-up to match the speed of the drivetrain. If this happens while the engine was at high rpms, it may dramatically exceed the redline. For example, if the operator is driving close to redline in 3rd gear and attempts to shift to 4th gear but unintentionally puts the car in 2nd by mistake, the transmission will be spinning much faster than the engine, and when the clutch is released the engine’s rpm will increase rapidly. This problem is not typically associated with automatic transmissions due to the lack of driver control over the shifting process. <!>

the above info about electronic shifting systems in false. most electronic systems will only shift in the engine will not violate its redline limits in its down shift. in the above example, if the driver is trying to shift in to 4th from 3rd but accidently shifts down to 2nd an electonic system like tiptronic will not allow that to happen, but if the driver is in 3rd and is punching it, the system will allow them in enter the redline area and beyond depending on the system. The same claim can not be me about DSG cars or the manumatic tranmission available in the newer VW's/Audi's without the AWD system <!>