ABD
Automatic Brake Differential - A traction control program which works in conjunction with the new ABS/5 brake system. The ABD is active up to 45 mph. The system applies brake pressure to the rear wheel with the least amount of traction.

ABS
Anti–Lock Brake System/Version 5 - ABS prevents wheel lock–up under hard braking or low traction conditions so control of the car can be maintained.

AHK
Anhangerkupplung (trailer coupling)

AHKS
Anhangerkupplung schwenkbar (pivoting trailer coupling)

Airbag
An automatically inflating bag in front of passengers in an automobile to protect them in the case of an accident. The airbag currently available on U.S. versions is inflated within fractions of a second by a gas generator located in the center of the steering wheel or in the dashboard. The sensors which trigger the airbag respond reliably to frontal impacts of a certain severity and angle, but not from violent movements of the car on a bumpy road, minor collisions or if the car is struck a heavy blow in the repair shop.

Airflow Sensor
The device which measures the amount of air being drawn into the engine. This information is used by the ECU/DME to determine the amount of fuel to be metered into the engine's intake system. In most fuel injection systems, this sensor measures the volume of air.

ASR
Traction Control

ATF
Automatic Transmission Fluid

Balance Shaft
A vibration-reducing engine refinement. Porsche 944/968 series engines, in an innovative refinement of existing technology, use two balance shafts, rotating in opposite directions and at progressively higher frequencies, to cancel out second order harmonic vibrations, resulting in smooth operation at all rpm ranges, especially in the upper rpm ranges, and big displacement 4-cylinder engines.

BHP
Abbreviation for "brake horsepower," or horsepower as measured with the engine on a dynamometer, rather than driving the car. There are two popular standards for the measurement of horsepower—the American SAE net and the European DIN. DIN may be converted to SAE by dividing the DIN bhp by 1.014. Although certain European models may have higher bhp, it may be the same as the U.S. version—just measured differently.

Camber
The extent to which a car's wheels tilt inward or outward. With positive camber, the top of a tire tilts outward from the body; with negative camber, the tire tilts inward.

CAN
Controller Area Network. A wired network used on cars. similar to PC networks in our homes and businesses.

Carrera®
The term Carrera, used for the first time on the 356 model, has always indicated a model of particularly high performance and sporting character within a Porsche Series type. The name is derived from the famous Mexican "Carrera Panamericana" road race and has often been applied in the past to sports racing models which were exceptionally successful on all the world's racing circuits.

Caster
An angle describing the difference between a line drawn vertically through a wheel's centerline and the axis around which that wheel is steered.

CDR
Compact Disk Radio

CEL
Check Engine Light

Chassis
The structural monocoque.

Compression Ratio
The ratio between a cylinder's volume with the piston at the bottom of its travel and at the top. The higher the compression ratio, the greater the potential power an engine will develop. Knock sensor technology, and computerized engine management allows the use of higher compression ratios without damage to the engine.

Coupe
A two–seater sports car with a relatively short fixed roof is known as a coupe (from the French word for "cut off"). Whereas coupe models always have two doors, it is possible for two additional seats to be provided in the rear.

CVN
Calibration Verification Number

DDD
Dynamic Driving Differential - A mechanical limited slip differential that exhibits differing lock factors under acceleration and deceleration.

DME
Digital Motor Electronics - Porsche's engine management system, the Bosch "Motronic" system, that controls both fuel injection and ignition functions.

DOHC
Dual Overhead Cam - A system of valve actuation utilizing separate camshafts for the intake and exhaust valves of a bank of cylinders.

Dr. Ing. h.c. F. Porsche
Doctor of Engineering honoris causa (Honorary Doctor of Engineering) Ferdinand Porsche.

Drivetrain
The engine, transmission, and all other components (such as differential) that transmit power to a car's wheels.

DSP
Digital Sound Processing

DTC
Diagnostic Trouble Codes

Dual Mass Flywheel (DMF)
An engine's power strokes and firing order produce crankshaft speed fluctuations, especially at lower rpm. This causes torsional oscillation of the entire drive train. This is heard as rattling or knocking of loose parts, such as gear wheels and shift elements that are not in the power flow. The solution was a flywheel having additional mass after the torsional damper, which dampens power flow oscillations entering the transmission.

Egas
an electronic feedback form of gas pedal to throttle control. As opposed to older cable operated controls. also known as "drive by wire"

EGR
Exhaust-Gas Recirculation

Engine Management
An automobile's computerized "brain" that monitors key engine parameters. also known as ECU, or engine control unit.

EOBD
European On Board Diagnosis

EU2/EU3/EU4
European exhaust emissions standard

GHV
Gurthhohenverstellung (seat belt height adjustment)

GPS
Global Positioning System

GW
Gateway

HFM
Heissfilmluftmassenrnesser (mass air flow sensor) (MAF)

Horizontally Opposed Engine
More commonly known as "boxer engines" in Germany, where they have always been popular, these engines have the two banks of cylinders pointing away from each other, 180 degrees apart, and the opposed pairs of pistons move in opposite directions.

KESSY
Keyless Entry keyless go/control unit

Knock Sensor
A monitoring device that recognizes detonation in an engine and sends a signal to the control computer, which retards the timing. Use of a knock sensor permits higher compression ratios and helps protect the engine from lowgrade fuel.

Lambda–Sensor Control
A closed–loop regulating system incorporating exhaust gas measurement to ensure that the proportions of air/fuel mixture are kept constant. Measures oxygen (O2) content in the exhaust.

LEV
Low Emission Vehicle

LHD
Left Hand Drive

Limited–Slip Differential (LSD)
A type of differential which limits the degree of variation in wheel speed between the two driven wheels, thus reducing wheel spin under conditions of poor traction. The limited–slip differential begins to restrict the power supplied to a spinning wheel by a predetermined amount, reducing the speed of rotation of the spinning wheel to that of the wheel which still has sufficient grip.

Litronic
Porsche's trade name for gas discharge headlamps which employ an electrical arc within a bulb filled with xenon gas.

LWR
Automatic headlight beam adjustment

MAF
Mass Air Flow sensor (hot-film air-mass metering sensor).

ME
Motronic with E-gas

MIL
Malfunction Indicator Light (same as CEL)

MMI
Man Machine interface

Monobloc
The industrial term for a complex assembly forged or cast as one piece. Specific to Porsche, monobloc brake calipers are complete alloy castings comprising both halves of the caliper assembly in one piece, rather than the more common method of caliper manufacture, which involves two "clamshell" caliper halves bolted together.

MOST
Media-Oriented Systems Transport. A fiber optic network used on cars.

MY
Model Year (MY05=Model Year 2005)

OBD II
On-Board Diagnostics II (version 2), mandatory on all MY 1996 cars and newer.

On–Board Computer (OBC)
This term refers to a "driving computer" that delivers information to the driver such as outside temperature, average fuel economy, odometer, miles remaining at current average fuel economy, etc.

PMNA
Porsche Motorsport of North America

POSIP
Porsche Side Impact Protection System

PSD
Porsche's Variable Limited Slip Differential

PSE
Porsche Sport Exhaust

PSM
Porsche Stability Management

PST2
Porsche System Tester 2

PTM
Porsche Traction Management (on Cayenne)

RDK
Reifen Druck Kontrolle (tire pressure monitoring system)

RHD
Right Hand Drive

RMS
Rear Main Seal. The crankshaft seal on the flywheel side.

RoW
Rest of World - Porsche designates NON US/Canada vehicles as RoW

SBS
Sprach-Bedien-System (voice control system)

Targa®
The 911 body style with removable roof panel, inspired by Porsche's racing victories in the Sicilian race through the street, the Targa Florio. Its design set a precedent for a sports car providing its owner with the structural rigidity and noise isolation of a coupe along with the open air qualities of a convertible.

TC
Traction Control

Tequipment
Porsche's line of accessories available only from Porsche

Tiptronic®
The Porsche Double Function Transmission offering both automatic and manual modes. In "automatic", the transmission adapts to the driver's driving style by selecting one of five shift maps. The Tiptronic control selects a shift map while constantly measuring five variables: throttle valve opening, engine rpm, speed, lateral acceleration and longitudinal acceleration. In the "manual" mode, the spring–loaded selector is tipped forward for upshifts and back for downshifts.

Torque Tube
Strong safety advantage of the transaxle Porsches — the 928, 944, 968 Series. The torque tube ties the front–mounted engine and rear–mounted transaxle together creating, in effect, a strong "central spine."

Torsion Bar
Used in four and six cylinder Porsche vehicles, torsion bars act as linear springs to suspend the weight of the vehicle. Up and down motions of the vehicle cause a twisting (torsional) force to be applied to the torsion bars. The bars behave in the same manner as a coil spring except they are straight as opposed to coiled.

TSB
Technical Service Bulletin. Porsche issues TSB's for part number changes, installation of options and accessories, approved oils, tires, wheels, etc.

TWC
Three-Way Converter (catalytic converter)

Unitized Body/Unibody
Body construction in which the car is built as one unit (monocoque) as opposed to the body being attached to a separate chassis or frame.

Variable Valve Timing
Consists of the ability to dynamically change intake or exhaust timing as performance or economy needs dictate. Generally controlled by engine speed.

VarioCam®
Porsche's patented system of creating variable valve timing. This system is unique in its simplicity (requires just one moving part) and sophistication (it is regulated by the DME).

Varioram®
Porsche's patented system of variable intake tract length. As rpm rises, the intake tract length is changed by opening valves to maximize torque across the rev range.

VIN
Vehicle Identification Number