Technique of A-Z: Our Chiptuning Lexicon


Additives are chemical additives in fuels, for example lubricants.


Four-wheel drive means, unlike front or rear wheel drive, that all four wheels are driven. This is usually the case with SUVs or SUVs. Four-wheel drive is available in two versions: Either the vehicle always (ie permanently) has such a drive or the driver can switch it on as needed.

Drive shaft and PTO shaft

The engine power in the car is transmitted via the drive shafts from the transmission output to the drive wheels. In vehicles with front-mounted engine and rear-wheel drive, there is a front-to-rear propshaft between the transmission and the so-called final drive. It ends in a differential gearbox - from where the axle shafts and drive shafts transfer the power to the wheels. Cardan shafts and all drive shafts on vehicles with independent suspension require joints. This compensates for possible movements of the drive unit or even the movements of the wheels during compression and rebound.


Exhaust manifold is a component referred to, which is attached directly to the cylinder head of the engine. In the manifold collect the exhaust gases collect first. The exhaust system is attached to the exhaust manifold with the silencer, explains the TV Nord in Hanover. In addition to the manifold on the exhaust side, there are also intake manifold - here sucked air reaches the cylinder head. In order to influence the engine characteristics, the pipes are tuned on the intake and exhaust side of the engine so that a desired performance and torque curve is achieved. For this, the tube lengths must be as equal as possible. This can result in the tubes of an exhaust manifold running together fan-like and one speaks of a manifold.


The automatic designates a possible transmission type of the car. In the automatic, the driver does not need to switch itself, he only presses gas and brake. The driver can choose between several driving levels and of course the reverse gear.


Biodiesel is derived from vegetable oils that are naturally derived from the energy of the sun. Vegetable oils are not of mineral origin and therefore are not subject to the mineral door. This makes biodiesel cheaper than mineral diesel.


So are the models with turbo diesel direct injection at Mercedes.


CDTI are called at Opel the turbo diesel direct injection.


So Mercedes calls its models with direct gasoline injection.


Common rail

The technical term common rail is part of the injection system. Common Rail initially means "common management". The common high-pressure injection line supplies all cylinders. The system is used in diesel engines with direct injection and in gasoline engines with so-called multipoint injection, explains the TV Nord in Hanover. In diesel engines injection pressures up to about 1600 bar are possible. During the injection process, the fuel is forced through the injector ("injector") into the combustion chamber. Within a combustion cycle it is possible with the common rail system according to TÜV to realize several injections per cylinder. Pre-injection ("pilot injection") reduces the usual, harsh combustion noise of diesel direct-injection engines.

CW value

CW value is the drag coefficient. He describes the Windschlpfrigkeit of each body, including a car. The lower this value, the windschlüpfiger is a vehicle.


Diesel fuel is a mixture of different hydrocarbons that is suitable as fuel for a diesel engine. Diesel is obtained from the distillation of Rohl as middle distillate. The main components of a diesel fuel include alkanes, cycloalkanes and aromatic hydrocarbons. Diesel engines have higher efficiency and lower fuel consumption than petrol engines, for example.


The differential allows a speed compensation between the two driven wheels of an axle. This is necessary because when cornering, the inner wheel travels a shorter distance than the outer wheel and thus the inner wheel needs less turns.

differential lock

Usually cars have a differential (differential), which allow the necessary, inter alia, when cornering different speed wheel rotations. But it has the disadvantage that on slippery roads, the drive wheel with the lower tire adhesion can spin and the vehicle does not progress. This can be prevented with the differential lock - the wheel with the best tire grip is then used for power transmission.


Torque is the force that is applied to a body and defined as a product of force and lever arm. The torque indicates the pulling power of the engine.

number of revolutions

The speed indicates the rotation of one motor per minute. Gasoline engines have higher speeds than diesel vehicles.


Too high speeds are dangerous for the engine, can lead to its destruction. A rev limiter should prevent this. In modern engines, the fuel supply is interrupted in order to prevent "over-turning" of the engine. This also excludes that unburned fuel can get into the catalyst. This prevents the fuel from igniting there and overheating and destroying the catalyst as a result of the afterburning. Due to an agreement of the automotive industry, fuel consumption is now reduced for most faster cars from a speed of 250 kilometers per hour - in a broader sense, this device can also be referred to as a speed limiter.

Rev counter

The tachometer measures the number of revolutions that a motor makes within a minute. The tachometer often contains a red area. When the red zone is reached, the driver knows that he must not accelerate the engine higher. The tachometer is integrated into the dashboard and is usually located in direct proximity to the speedometer.


Injector says nothing else than that the fuel is injected electronically into the combustion chamber.


FAP refers to the PSA Group (Peugeot, Citrön) the diesel particulate filter that filters soot particles from the exhaust gases. The group is a pioneer in this technology.


Designation in the VW group for gasoline direct injection.


HDI refers to the PSA Group (Peugeot, Citrön) the Turbodieseldirekteinspritzer.

Cubic Capacity

The cubic capacity is calculated from bore times stroke. Here bore means the diameter of the cylinder, stroke the way the piston travels in the cylinder. After the displacement also measures the vehicle tax.

hybrid drive

In a hybrid drive, the car has not just one, but two engines. In most cases, these are an electric and a gasoline engine. Rarer is there also the variant electric / diesel engine. An electronic control system ensures that the most efficient engine is used, depending on the operation. The fuel motor also serves to charge the batteries of the electric motor so that the vehicle does not need to be plugged in.


JTD is in the Fiat Group (Fiat, Alfa, Lancia) the abbreviation for the Turbodieseldirekteinspritzer.

Air systems

The cold run controller is a mechanical component that ensures that in older cars in the first start-up phase, a lean gasoline-air mixture is available. With the cold run regulator older gasoline engines create better emission standards, so that a subsequent installation often worth due to the savings in the car Steering. Cold run control is only available for petrol engines.


The so-called knocking in a car engine causes power losses and leads to a high thermal and mechanical load. Result may be engine damage. The background is that in a gasoline engine, a fuel-air mixture is compressed by the piston and finally ignited at a specific time by a spark plug. If there is insufficient knock resistance of the fuel - ie, too low an octane number - the fuel-air mixture ignites prematurely by itself. The upwardly moving piston then receives a recoil - the resulting noise is called knocking.

knock sensor

A knock sensor is used for optimum combustion of fuels in engines. It is part of the electronic knock control system. This system in the car helps to prevent the so-called knocking combustion: It is harmful to the unit, since it can come in the cylinder to high pressure peaks and very high temperatures. Background of the problems may be fluctuations in fuel quality or low octane fuels. The knock sensor detects appropriate information and forwards it to the electronic engine management. There they are compared with the specifications. Injection amount and time are then corrected and the ignition is adjusted so that knocking combustion no longer occurs.


KW is the abbreviation for kilowatts. This unit is the power of the engine.


In turbocharged or supercharged engines, an intercooler has an important function. It compresses the air and in the end also ensures better performance. Basically, in engines with exhaust gas turbochargers or compressors, a so-called boost pressure is generated in the intake tract of the engine. The compressed air heats up - but warm air has a larger volume than cold air. The intercooler cools the intake air before entering the combustion chamber, thus increasing the degree of filling - it fits more cold than warm air into the combustion chamber.

Engine oil

To ensure easy running of the car and to prevent overheating, all engines have sufficient lubricants. In addition to the lubrication of the individual components in the engine, the oil also takes over the task of sealing in the cylinder between the combustion chamber and the oil sump and the cooling of the piston crown. Likewise, the oil absorbs deposits from the engine and keeps them in suspension. These are washed out during regular oil changes. There are single-grade oils used only in winter, and there are multi-grade oils suitable for summer and winter.

octane number

The octane number indicates the knock resistance (resistance to auto-ignition) of fuels. The higher the octane number, the more resistant to knocking is the fuel. For example, an octane number of OZ = 95 of a gasoline would mean that the knock resistance of the gasoline corresponds to a mixture of 95% isooctane and 5% n-heptane. One can distinguish between different octane numbers: ROZ = Research - (researched) octane number, MOZ = engine octane number, SOZ = road octane number and FOZ = front octane number.

oil filter

The engine needs oil for its work. However, combustion residues may be present in this oil. An oil filter filters out these residues.

oil change

The oil needed in the engine gets dirty after some time. But to keep the engine running well, the oil has to be changed after a certain period of time. The periods for oil changes are indicated by the mileage. Modern vehicles need only every 30,000 or even just every 50,000 kilometers to an oil change. Many cars can also calculate the service intervals themselves and log on by on-board computer by itself.

Piezo technology

There are injectors and there is the so-called piezo technology, which is to provide in the car in the fuel injection for an even more accurate and faster control. But the piezo technique is also used elsewhere. These include parking systems for distance measurement or electronic push-buttons. According to TV information, the piezo technique is based on the so-called piezoelectric effect: If an electrical voltage is applied to certain crystals, then they react with a mechanical voltage. In practice, this means that so-called piezo actuators in the injection expand or contract as quickly as possible by applying a voltage and thus just allow a particularly accurate injection.


The connecting element in an engine between the piston and the crankshaft is called the connecting rod. It transfers the force that is generated during the combustion cycle, from the piston via the piston pin to the crankshaft. For large series engines, the connecting rods are usually made of high-strength steel. In some motorcycle and sports car engines, on the other hand, titanium connecting rods are used. Titanium has approximately the same tensile strength as steel, but its specific gravity is more than 40 percent lower than that of high strength steels. With proper design, the connecting rods can therefore be built much lighter and contribute to the desired in sporty vehicles weight reduction.


For some drivers the most important thing about a car. PS states the horsepower. Meanwhile, the unit PS, however, replaced by the kilowatts (KW).

Pump nozzle

The pump-nozzle system is a special fuel injection in the car engine. According to the TV Nord in Hanover, this system has its own pump-nozzle element for each cylinder of the engine, which consists of a pump part, a nozzle part and the solenoid valve. Each unit injects the fuel in a coordinated amount at a precise time in a combustion chamber. The system allows high injection pressures even without the usual high-pressure injection lines. Among the advantages of the technology in comparison with other injection systems is, among other things, a lower fuel consumption with better power output.

soot particle filter

They are on everyones lips because of the particulate matter discussion: soot particle filters are used to eliminate the carcinogenic solid particles in the exhaust gases of diesel engines. According to the TV Nord in Hanover, the best solution so far has been the so-called ceramic monolith filter. Here, the exhaust gases flow through the porous, honeycomb-shaped structure of the filter, whereby the particles are deposited in the pores. In order to prevent clogging of the filter, it must be "regenerated" at certain intervals, that is to be cleaned.

naturally aspirated

The naturally aspirated engine is the name given to an internal combustion engine. In a naturally aspirated engine, the fuel is not injected into the combustion chamber, but the piston sucks it. Is known the engine bsp. as a suction diesel in contrast to the modern diesel direct injection.

manual transmission

In contrast to the automatic transmission, the driver has to perform the shifting operations himself in a manual transmission. To do this, in addition to the brake and the throttle, he must also activate the clutch. With a transmission, the power of the engine is passed on.

fuel cut

The fuel cut-off in the car is used to reduce fuel consumption and exhaust emissions. Basically, the term fuel cut is understood to mean the targeted reduction or interruption of the fuel supply of an internal combustion engine in the so-called push mode. For overrun it comes, for example, when Gaswegnehmen, brakes or when driving downhill - the vehicle then no longer runs by engine power, but is moved forward by its inertia or the slope.

Vibration Giro meters

A difficult, almost unspeakable name. Nevertheless, he is indispensable in the car for certain systems. Permanently installed navigation systems and Electronic Stability Programs (ESP) work with the help of a so-called vibrating girometer. A girometer basically serves to detect angles of rotation - changes around the vertical axis of the vehicle - the so-called yaw angle. The device basically tracks the position of the car like a compass and records every turn, explains TV Nord in Hanover. In the navigation system, this function is used to support the route detection - among other things, if, for example, in a tunnel, no satellite connection is available. The ESP calculator, on the other hand, draws conclusions from the data on possibly necessary braking interventions.


Diesel vehicles are also called "self-igniters", because with them the fuel ignites spontaneously in the extremely compressed and hot air. In contrast to the gasoline engine, a diesel can therefore dispense with spark plugs. A diesel only has glow plugs which ensure the right temperature during a cold start. Diesel engines are named after their inventor Rudolf Diesel.

Seqünzielles manual transmission

In modern seqünziellen transmissions in the car, the switching process is triggered by buttons or so-called paddles on the steering wheel. This solves solenoid valves electrically, which trigger both the hydraulic actuation of the clutch and the switching itself, explains the TV Nord in Hanover. The choice of the aisle is controlled by electronics. In some embodiments, it is possible to choose between different switching programs with which, for example, winter conditions, a particularly energy-saving or a sporty driving style can be taken into account.


As TDCI Ford calls its turbodiesel direct injection.


Designation of the VW group (Audi, Seat, Skoda, VW) for turbodiesel direct injection. The term is protected, which is why other manufacturers may not use this abbreviation.

Cruise control

A cruise control - also called speed control system - ensures that the vehicle maintains the speed once selected. Braking is not affected.

Turbocharger and compressor

Are cars with turbochargers or compressors faster? The simple answer is that they are used in the car to increase engine power. But what exactly are turbocharger and compressor? Basically, behind each of the idea behind the engine to supply more combustion air or fuel-air mixture. In the exhaust gas turbocharger, the energy of the engine exhaust gases is used to drive a turbine wheel that runs on a common shaft with a so-called compressor wheel. This wheel pushes the intake air into the combustion chamber of the engine. The turbine reaches speeds of more than 100,000 revolutions per minute. Unlike exhaust turbochargers, compressors are usually driven directly by the crankshaft or belt, so they also absorb some of the engines power. They respond more directly to desired speed increases, as exhaust turbocharger. Modern developments use mechanical loaders that are powered by electric motors. The usual power losses do not occur here.


TÜV actually designates the Technical Inspection Association. Colloquially, this also means the main investigation, which is due every two years and the TÜV or DEKRA take over.


Valves can be found in an engine in the cylinder. On the one hand, they allow the air for combustion and, on the other hand, the exhaust gases out again.

Four-stroke engine

Four-stroke engine is a description of the operation of a motor. Modern engines work after these four cycles: suck in air compress air ignite the fuel exhaust fumes out.


CommonRail systems today use pre-feed pumps for fuel injection in diesel engines. The prefeed pump delivers the fuel from the tank under slight pressure into a so-called pump reservoir. From there, a high-pressure pump is supplied, which then compresses the fuel so that it receives the necessary injection pressure for combustion.


To start a diesel engine belongs to the so-called pre-gliding, which is alien to the gasoline engine. The reason for this is that when cold starting the diesel, the temperature reached in the compression process for Entzönden the fuel is not sufficient. The mixture must therefore be preheated. This task is performed by glow plugs, which protrude into the combustion chamber. Part of the injected fuel evaporates on the hot glow plug tips and ignites. In the past, the Vorgülh process took several minutes, with modern vehicles just a few seconds.

toothed belt

Diesel drivers know the problem: Can not overestimate the life span of a toothed belt - this can have fatal consequences. Timing belts are among the most heavily used parts in the engine compartment of a car. Therefore, it has come in the past again and again to toothed belt breaks, which usually had major engine damage. Engine manufacturers are tackling this problem today with wider timing belts with reinforced substructures. Shortening the replacement intervals of the toothed belts should also prevent possible damage. Basically, the toothed belt is used to drive the so-called valve train, so especially the camshaft. The injection pump can also be driven by the toothed belt.

Two-stroke engine

Two-stroke engines are now out of fashion. The reason: they just consume too much. However, since they have compact dimensions, two-stroke engines are still used in mopeds, but not in cars. This is mainly because they consume significantly more fuel than four-stroke engines and emit more pollutants - especially hydrocarbons. This explains the TV Nord in Hannover. Because of their compact and lightweight design, however, the two-stroke engines are still used in vehicles with a small displacement, for example in mopeds and mopeds. The term two-stroke engine is misleading, according to the TV. As with the four-stroke engine, four so-called cycles (intake, compression, operation, exhaust) are required for one working cycle. However, the two-stroke engine needs only one crankshaft revolution, the four-stroke engine requires two revolutions.


In the cylinder, the piston of the engine moves up and down. There is also the combustion of the fuel instead. Common are engines with four-cylinders or smaller vehicles with three-cylinders. Larger car models also have six-, eight-, ten- or twelve-cylinder.

Cylinder head gasket

The cylinder head gasket seals the transition area between the engine block and the cylinder head. This should be the oil and cooling water channels are sealed off against the combustion chamber. The seal itself must possess several capabilities and properties. This also includes heat resistance, in order to cope with the high temperatures of the combustion chamber. In addition, it must be heat-conducting, so that the heat of the combustion chamber derived and the formation of so-called hot springs is avoided. In addition to necessary corrosion resistance and pressure resistance, for example, to avoid leaks. The seal also has to be elastic, so that unevenness and thermal expansion can be compensated.