- A-Pillar
The
roof supports on either side of a car's windshield. The
letter A indicates that these are the first pillars from
the front of the car.
-
- Active
Safety Features
Safety
features that require some action by a vehicle's occupants,
such as seat belts.
-
- Aerodynamic
Drag
Air
resistance encountered as a car moves down the road.
-
- Air
Bag
A safety
device that deploys in a severe frontal crash. Air bags
are located in the steering wheel hub and in the passenger
side dash pad.
-
- Air
Conditioning Compressor
A pump
that circulates refrigerant chemical through the air conditioning
system.
-
-
Air Dam
A spoiler
located beneath the front bumper. Though it serves a cosmetic
purpose, an air dam is usually shaped to reduce the airflow
under the car, lower aerodynamic drag and reduce lift.
It can also be contoured to increase the airflow to the
radiator.
-
- Air
Filter
A component
that contains a cartridge made of special material, usually
a form of paper, which will allow air to pass through
but will trap small airborne particles. The air filter
becomes saturated with dirt over time and needs periodic
replacement.
-
- Air/Fuel
Mixture
Liquid
fuel, gasoline or diesel, must be converted to a vapor
before it can be ignited in a combustion
chamber to release its kinetic
energy. A gasoline engine runs most efficiently when the
fuel/air ratio is around one part fuel to 14 parts air.
This mixing and atomizing of fuel and air is done either
in a carburetor, which is not found on modern vehicles,
or by a fuel injection system.
-
- All
Season Tire
A
tire that provides traction under all weather conditions.
-
- All
Wheel Drive
Another
way of saying Four-Wheel Drive (4WD),
although All-Wheel Drive (AWD)
usually operates full time and does not require the driver
to actively engage the system. The system automatically
distributes power between the front and rear wheels as
needed.
-
- Alternator
A
component of the electrical system, it converts 12-volt
DC (Direct Current) from
the battery into AC (Alternating
Current) at the rate of 13.8 to 14.2 volts. The
alternator also provided electric power to operate the
engine and accessories.
-
- Anti-Lock-Braking
System
(ABS)
A
braking system that uses electronic sensors to detect
when any of the wheels have locked up, or are about to.
When the brakes are applied with maximum force, such as
in a panic stop, the ABS pumps the brakes up to 30 times
a second. This action prevents the wheels from locking
up and allows the driver to maintain steering control,
although it does not stop the car in a shorter distance.
-
- Anti-Roll
Bar
A
suspension component that reduces body roll.
-
- Antifreeze
A
liquid that cools a car's engine but will not freeze.
Antifreeze was once used only in cold weather but today's
cars use antifreeze, more properly called coolant, year
round. It should be checked regularly and changed at specified
intervals.
-
- Automatic
Transmission
A
transmission where the gears are shifted automatically
without any input from the driver. These transmissions
have 3, 4 or 5 speeds. In 4 and 5 speed transmissions,
the highest gear is for overdrive, which provides better
gas mileage at cruising speeds.
-
- Axle
A
steel shaft that connects the differential
to the drive wheels.
B-Pillar
The roof support behind the front doors. It's the second
support pillar from the front of the vehicle.
- Ball
Joint
A flexible ball and socket joint used primarily in front
suspensions.
- Base
Model
The least expensive version of a vehicle model. Often
these have few power accessories, the smallest engine,
and a manual transmission.
- Beam
Axle
A rigid axle
supporting the non-driven wheels.
- Beltline
The line that separates a car's greenhouse
from its lower body.
- Block
Heater
An accessory which uses electric power to keep an engine
that's been turned off from becoming too cold, which makes
it hard to start in extremely cold climates.
- Body
Material
What the body is made from. In most vehicles, this is
a combination of welded steel stampings. Some vehicles
are made of fiberglass or composite materials such as
carbon fiber, though this type of construction is usually
found only in exotic sports cars or racing cars.
- Body
on-frame Constuction
A method of vehicle construction in which the body, engine,
driveline and suspension are bolted to a frame or
chassis.
Most light trucks are built this way but few passenger
cars.
- Bore
and Stroke
Bore is the diameter of a cylinder
and stroke is the maximum distance the piston travels
within the cylinder. This is expressed in inches or millimeters
(3.39 x 3.39 in, 86.0 x 86.0mm). The volume of a cylinder
times the number of an engine's cylinders is its displacement.
- Brake
Caliper
A yoke shaped component of a disc-brake system. It contains
the brake pads, a hydraulic cylinder and straddles the
brake disc.
-
- Brake
Fade
A loss of the brake's ability to stop the car. This occurs
when the brakes heat up after heavy usage, as when driving
down a long grade.
- Brake
Pads
The components of a disc-brake system that grip a disc
and provide the force that brakes the vehicle. Hydraulic
cylinders in the brake caliper actuate them.
-
- Brake
Shoes
The components of a drum-brake system that apply pressure
to the brake drums and bring the vehicle to a stop. The
surface of the shoes is a high-friction material that
comes into contact with the inside of the drums as the
shoes are pushed apart by a hydraulic cylinder.
- Brake
Discs
Brakes that use a disc connected to the wheel and a caliper,
containing brake pads, that's attached to the wheel hub.
When a driver applies the brakes, the pads are pushed
against the disc by hydraulic force. The disc is pinched
between a set of calipers and, as pressure is applied,
slows the wheel and brings the car to a stop.
- Brakes,
Drum
Brakes that use an iron casting shaped like a shallow
drum that rotates with the wheel. Curved brake shoes inside
the drum are pushed against the inside of the drum by
hydraulic pressure to provide braking.
- C-Pillar
The third roof support on a vehicle. On a two-door or
four-door, it's the pillar behind the rear-seat window.
On a sport-utility or station wagon, it's the pillar behind
the rear door. Additional pillars continue the alphabetic
system; there may be a D-pillar and so forth.
- Camshaft
A shaft with a cam, shaped like an eccentric circle, for
each of an engine's intake and exhaust valves. As the
camshaft rotates, each cam comes in contact with either
a pushrod
or rocker
arm
and converts rotary motion into linear motion that ultimately
opens the valve (a spring closes it). One or more camshafts
regulate the opening and closing of the valves in all
piston engines.
- Camshaft,
Overhead
A valvetrain
in which the engine's camshaft is in the cylinder head.
This configuration locates the camshaft closer to the
valves, as opposed to an in-block camshaft location, which
allows the valvetrain components to be stiffer and lighter.
In a single-overhead-cam (SOHC)
layout, one camshaft actuates all of the valves in a cylinder
head. In a double-overhead-camshaft (DOHC)
layout, one camshaft actuates the intake valves, and the
other operates the exhaust valves.
- Capitalized
Cost Reduction
An up-front or down payment on a lease which can reduce
monthly payments. The trade-in value of a vehicle may
also be applied in place of, or in addition to, this payment.
- Carburetor
The fuel system component that meters and mixes fuel and
air in the proper proportion. The carburetor also atomizes
this mixture and directs it to the intake manifold that
distributes it through passages to each combustion
chamber.
- Catalytic
Converter
A component of the exhaust system -often simply called
a "catalyst" - which chemically converts smog-producing
emissions into less harmful compounds.
- Chains
Accessories that can be fitted to a vehicle's driving
wheels to improve traction in snow. These are required
for winter mountain driving.
- Chassis
The underlying structure of a vehicle. In vehicles with
a frame, the chassis generally includes all of the mechanical
components attached to the structure. In cars with unitized
construction, the chassis includes all the components
except for the body.
- Cladding
Protective and decorative panels along the lower body.
These panels protect under areas from flying road debris.
- Closed
End Lease
Also called a walk-away lease, it gives the lessee the
choice of returning the vehicle to the dealer or buying
it for the purchase option price when the lease term is
up.
- Clutch
A disc-shaped mechanical device that disengages the engine
from the transmission.
- Clutch-Starter
Interlock
A safety device that prevents a car from being started
while it's in gear. The clutch
must be depressed for the engine to start.
- Coachwork
Body building as applied to an automobile. Usually used
to describe custom body work. A seldom used word, it is
most often seen in reference to vintage or classic cars.
- Coefficient
of Drag (Cd)
The measure of the aerodynamic efficiency, or drag, of
a vehicle. An aerodynamically efficient vehicle would
have a drag coefficient, or "Cd," of about 0.30, although
even lower, numerically stated, Cds are not uncommon.
- Combustion
Chamber
The space remaining in the cylinder
when the piston is at the top of its travel. The combustion
chamber is mostly in the cylinder head and also contains
the valves
and spark plug. The chamber is shaped to promote more
efficient and cleaner combustion.
- Compression
Ratio
The ratio between the volume of a cylinder
and combustion
chamber
when the piston is at the bottom of its stroke and when
it's at the top. Within limits (see Detonation),
the higher the compression ratio, the more power is produced.
- Concept
Car
A hand-built vehicle designed by a manufacturer to test
public reaction to a particular design. Some concept vehicles,
also called show cars of dream cars, actually make it
into production but most wind up in museums.
- Connecting
Rod
An I-beam shaped metal rod that connects a piston to a
throw on a crankshaft.
- Cooling
System Capacity
The specified volume of coolant required to fill the cooling
system, expressed in liters or quarts.
- Coupe
A hardtop vehicle with two side doors and less than 33
cubic feet of rear interior volume, according to measurements
based on SAE standard J1100. A two-door car with more
rear-seat room may be called a two-door sedan.
- Crankcase
The portion of an engine block that contains the crankshaft,
main bearings and oil sump.
- Crankshaft
A heavy shaft with one or more cranks, or "throws," that
are attached by connecting rods to the engine's pistons.
As the piston moves up and down in the cylinder, its linear
motion is converted to rotary motion by the crankshaft,
which, in turn is connected through either a mechanical
(clutch)
or hydraulic (torque converter) coupling to the transmission.
- Crumple
Zone
Front and rear portions of a vehicle's body that are designed
to crush progressively to better absorb the energy of
a crash.
- Cylinder
The tubular passage through which a piston moves up and
down. Automotive engines consist of anywhere from four
to 12 cylinders that are arranged in either a straight
line or in a V arrangement within the cylinder block.
- Cylinder
Head
An aluminum or iron casting which contains the combustion
chambers,
the intake and exhaust ports, and much or all of the valvetrain
-
-
-
- Daytime
Running Lamps (DRLs)
Lights that automatically turn on when a vehicle is started,
making it more visible during daylight hours.
- Detonation
Also known as "knock," it is caused by the spontaneous
combustion of the fuel/air mixture in a combustion chamber.
Detonation can be a result of too low an octane fuel (see
Octane),
improper fuel/air mixture or incorrect ignition timing,
or a combination of these things. It is a symptom of an
engine that is out of tune.
- Differential
A gearbox that distributes power from one source, a driveshaft,
to a pair of axles.
A standard differential also allows the driving wheels
to rotate at different rates so that a car can go around
corners without spinning the inside wheel. Sometimes called
a "rear end."
- Differential,
Center
A component of some four-wheel-drive systems that distributes
power to the front and rear differentials.
- Differential,
Final-Drive Ratio
A measure of the gear reduction provided by a
differential,
expressed as, for instance, 3.07:1. In this instance,
the driveshaft
leading from the transmission
makes 3.07 rotations for each rotation of the engine.
- Differential,
Limited-Slip
A differential
with a mechanism that assures that some torque
is always distributed to both wheels, even when one is
on very slippery pavement.
- Differential,
Locking
A differential
whose two outputs can be locked together, eliminating
any differential action but maximizing traction.
- Differential,
Ring-and-Pinion Gear
A gear set consisting of a small gear (the
pinion) that turns a large-diameter circular gear
(the ring).
- Displacement
The combined volume of an engine's cylinders,
expressed in cubic inches, cubic centimeters or liters.
- Downforce
Downward pressure created by a vehicle as it moves through
the air. This can be affected by the shape of the vehicle's
body and by add-on aerodynamic devices such as spoilers.
- Driveline
The driveshaft,
differential
and axles.
- Driveshaft
A solid or tubular shaft that transmits power from the
transmission
to the differential.
- Drivetrain
The components that provide power and transmit it to a
vehicles wheels, including the engine, transmission,
driveshaft,
differential
axles
and hubs.
-
- EGR
Exhaust-gas recirculation is an emission reducing technique
that mixes some exhaust gases with the incoming fuel.
-
- EPA
Mileage Ratings
(MPG)
The
distance a vehicle can travel per gallon of gasoline in
specific conditions such as city and highway driving as
determined by the Environmental Protection Agency. These
are expressed as miles per gallon (MPG) and are determined
in tests conducted over a specific driving course under
laboratory conditions. The city fuel-economy test, also
used to test emissions compliance, is based on a drive
through typical Los Angeles urban traffic in the mid 1970s.
-
- EPA
Passenger Volume
(cu. ft.)
A
vehicle's interior volume as measured according to standards
established by the Environmental Protection Agency.
-
- Emissions
controls
Components
that reduce exhaust emissions, including the catalytic
converter
and EGR
system.
-
- Engine,
"Boxer" or Horizontally Opposed Cylinders
An
engine with its banks of cylinders
arranged opposite each other in a flat configuration.
It has a low center of gravity and presents a lower aerodynamic
profile.
- Engine,
Diesel
An engine that uses diesel fuel rather than gasoline.
-
- Engine,
Inline
A
type of engine that has its cylinders
arranged in a straight line.
-
- Engine,
V-Type
An
engine with its cylinders,
from two to as many as 12 in common practice, arranged
in V-shaped banks.
-
- Engine,
Water/Air-Cooled
Water
cooled engines circulate liquid through the engine block
and cylinder
head,
then through a radiator, to dissipate heat caused by combustion
and friction. Air cooled engines use fins to dissipate
the heat to the atmosphere, although they are usually
aided by a fan in automotive applications.
-
- Engine-Control
System
Modern
engines use a computerized system to regulate their operation.
It uses sensors to monitor and adjust the fuel/air mixture,
combustion timing and other functions to keep the engine
operating at its maximum efficiency according to pre-programmed
schedules.
Ergonomics
The
science of designing objects to better accommodate human
beings. This term is used commonly for interior component
placement.
-
- Excess
Mileage
Any
mileage above the standard annual allowance. At lease
end, the lessee pays a predetermined charge for each
excess mile. This does not apply if the lessee buys
the car.
Facia or Fascia
The front of a vehicle - grille, headlights, bumper and
valance.
-
- Floorpan
The
largest stamped metal part in a car's body, it forms the
floor and also provides the attachment points for many
of the car's mechanical parts.
-
-
Flywheel
A
metal disc bolted to the end of the crankshaft.
The inertia of the spinning flywheel while the engine
is running smooths the engine's operation.
-
- Four-Wheel
Steering
A
rarely found steering system in which the rear wheels
as well as the fronts can be steered. This type of steering
as movable steering
parts on all wheels.
-
- Four-Wheel-Drive
(4WD)
A
type of drive system where power is fed to all four wheels
through a system of driveshafts,
differentials
and axles.
4WD can be full-time or part-time with the driver selecting
whichever mode is preferred.
-
- Front-wheel-Drive
A
type of drive system where power is fed to the front
wheels.This type of drivetrain
usually has tranverse mounted transmission
and engine all in the forward area of the vehicle
-
- Fuel
Injection
A
system that delivers a spray of fuel to an engine in the
proper amount. In modern engines, fuel injection is quite
sophisticated and is controlled by the engine's computerized
management system. There are several types of fuel injection
including Throttle-Body, which sprays the fuel into a
manifold for distribution to each cylinder, and Port Injection,
which sprays the fuel directly into the intake
port.
Fuel injected cars typically have an electric fuel pump,
an inline fuel filter and a fuel pressure regulator in
the system.
-
Gap Protection
A form of insurance which pays the difference
between what is covered by conventional insurance and
what's owed on a lease if a leased car is stolen or wrecked.
-
- Global
Positioning Satellite
(GPS)
See
Navigation System.
-
- Greenhouse
The
portion of a car's body above the beltline.
-
- Gross
Vehicle Weight Rating (GVWR)
The
combined weight of a light truck and its load-carrying
capacity.
-
- Ground
Clearance
The
distance from the ground of the lowest point on a vehicle's
undercarriage.
- Horsepower
The
standard unit of measurement of an engine's power. One
horsepower is the amount of energy needed to lift 550
pounds one foot in one second.
- Hydraulic
fluid
The
fluid in a brake system that transfers the force of braking
from the brake pedal to the calipers or brake shoes that
ultimately slow wheel rotation. Though the fluid operates
in a closed system, it requires regular checking and occasional
replacement.
- Ignition
System
The components of an engine that cause a spark plug to
arc and ignite the fuel/air charge in the combustion
chamber. These components include, in addition
to the spark plugs, a unit that sends electricity to the
spark plug at the correct interval. Commonly known as
a distributor, it is a fairly simple device in older vehicles
but is a sophisticated, computer controlled component
in more modern engines.
-
- Induction
System
The
components of an engine that provide its fuel. These may
include, in older engines, a carburetor
and intake manifold. In more modern engines a sophisticated,
computer controlled fuel injection system is the main
component of an Induction System.
-
- Instrument
Panel
(IP)
The
cluster of gauges which display vehicle operating data.
-
- Intake
Port
A
passage in a cylinder
head leading from the intake manifold to the intake valve.
-
- Internal
combustion engine
An
engine in which a fuel/air charge is compressed within
a combustion
chamber and ignited to release its kinetic
energy, which exerts force on a piston, which transfers
the energy to a crankshaft
and, ultimately, through the driveline, to the driving
wheels. All automotive engines are of this type.
-
- Jack
An apparatus for hoisting a part of a car from the ground
to aid in repairs. Most jacks sold with cars are scissors
or bumper jacks and are used for emergency tire changes.
-
Jumpstart
Using a set of cables (called jumper cables) to start
a car with a dead battery by connecting them with a
good battery. While most jumper cables connect one car's
battery to another, new systems with cables connected
to 12-volt battery packs are becoming increasingly popular
with drivers living in cold climates and remote areas.
-
Lease Term
The number of months a lease is in effect.
-
- Leasing
A
popular alternative to the traditional ways of buying
a vehicle - paying cash or financing. The arguments for
leasing: You can get a car for very little money up front.
You pay less money every month. You get more car for the
money, and you get to drive a new car more often because,
presumably, you re-lease every two, three or four years.
The argument against it is that at the end of the lease,
you own nothing. Leasing is not recommended for people
who tend to keep a long time and people who drive a great
deal. Buyers who are uncertain about which path to take
should compare the costs for each option.
-
- Lessee
The
buyer who leases a car or truck.
-
- Lessor
The
dealer or finance company that offers and administers
the lease.
- Manifold
Exhaust
A component of the exhaust system that combines the passage
from each exhaust port into one collector that directs
exhaust gases to the catalyst, mufflers
and ultimately the tailpipe. The shape of the passages
in an exhaust manifold is carefully tuned for maximum
efficiency.
-
- Manifold,
Intake
A
component of the induction system that distributes the
fuel/air mixture from its source, a carburetor
or fuel
injection system,
through carefully tuned passages to each cylinder.
-
- Manufacturer's
Suggested Retail Price (MSRP)
The
price of a vehicle, and its options that is set by the
manufacturer. Sometimes called the sticker price, it is
a guideline. The negotiated final price may be higher
or lower, depending on the demand for that particular
model. Some models can sell for more than the MSRP, while
others can sell for less.
-
- Master
cylinder
The
component of a braking system that forces hydraulic fluid
under high pressure to the brakes at each wheel. It has
a reservoir that contains the brake,
or hydraulic fluid,
and is part of a larger unit in power brake systems.
-
- McPherson
Strut
A
common suspension component, the strut combines the springs
and shocks into one unit.
-
- Mid-engine
Configuration
A
car that has its engine behind the passenger compartment
but in front of the rear wheels. Usually found in two-seater
sports cars such as the Ferrari Dino and Toyota MR2.
-
- Monocoque
See
"Unibody."
-
- Monroney
Label
The "sticker" on a new car -also called a Monroney label
after the Senator who wrote the legislation requiring
it -is pasted on a window of the vehicle. It shows the
base price, all standard equipment, itemized prices of
manufacturer-installed options, transportation or freight
charges (also known as destination or delivery charges)
and the total manufacturer's suggested retail price (MSRP).
The Monroney label also includes details about the average
fuel economy for the vehicle, although this is sometimes
found on a separate sticker, the Environmental
Protection Agency (EPA) Fuel Economy Label.
-
- Muffler
A
canister in the exhaust system that contains baffles and
other material that silences a car's exhaust.
- Navigation
System
An increasingly popular option which uses orbiting satellites
to determine a car's position which can be shown on a
map that's displayed on a dashboard video monitor.
- Normal
Wear and Tear
The amount of deterioration that is permissible over the
term of a lease.
-
- Normally
aspirated engine
An
engine without a supercharger.
- Octane
The measure of the anti-knock (see Detonation)
properties of gasoline. The higher the octane number,
the less likelihood of knocking.
-
- Odometer
An
instrument that displays th |
