A-Pillar to Axle

A-Pillar or A-Post
The front pillar that supports the windshield and the front of the roof.

Accelerator
The pedal on the driver's side floor that is linked to the throttle. It controls the amount of fuel-lair mixture delivered to the engine and ultimately determines the speed of the car.

Adjustable Shock Absorbers
These shock absorbers allow the driver to vary the ride from the driver's seat while the vehicle is in motion. In the case of some cars, the shocks can be adjusted for "soft," "normal" and "firm." Turning the control activates an internal motor in the shocks, adjusting the damping valve to control the ride.

Aerodynamic Drag or Air Resistance
The shape of any object creates air resistance when traveling at speed. The more streamlined the vehicle, the less air resistance; the bulkier the vehicle, the greater the air resistance. It has been proven that the more aerodynamically efficient a vehicle is, the less horsepower it requires to maintain speed, which increases fuel economy. (Also see: Drag Coefficient)

Air Bag
A device, usually located in the center of the vehicle steering wheel, that inflates in a frontal collision in order to protect the driver from impact against interior vehicle components. When triggered, the air bag inflates in approximately 30 milliseconds.

Air Cleaner
A device mounted in the air induction system for filtering dust and dirt from air being drawn into the engine.

Air Dam
A spoiler below the front bumper to reduce aerodynamic lift, drag and turbulence by diverting airflow around, rather than under, the vehicle. It also improves air flow through the radiator and air conditioning condenser.

Air-Fuel Mix
Ratio by weight of air and fuel in the engine's cylinder.

Air Injection
A system that injects air into the exhaust ports of the engine for combustion of unburned hydrocarbons in the exhaust gases, thus producing "cleaner" exhaust emissions.

Air Scoop
An aerodynamic device or opening used to duct cool outside air to some part of the car generally the engine air intake, the brakes or the radiator.

Alignment
Generally refers to wheel alignment, which is the proper adjustment of the car's front and rear suspension for camber, toe, caster and ride height.

Alloy Wheels
A generic term used to describe any non-steel road wheel. Most alloy wheels contain either aluminum or magnesium. These wheels are known for their light weight and strength.

All Wheel Drive (AWD)
A drivetrain where both front and rear axles transmit power to the wheels at all times. The Sentra Wagon and the Axxess AWD model use this type of drivetrain. If slippage occurs at the front wheels, power is transferred to the rear wheels and vice versa through a viscous coupling

Alternator
A part of the electrical system which converts mechanical energy from a drive belt into electrical energy to operate the ignition, electrical accessories and to charge the battery.

Anti-Backfire Valve
Works with the air injection system and prevents the rich, unburned exhaust gases from mixing explosively with fresh air, which would cause a backfire.

Antifreeze
Any of several substances (typically ethylene glycol) mixed with water and added to the car's cooling system to prevent freezing of the coolant in winter. It also inhibits formation of rust and other deposits that would tend to clog the radiator and coolant passages, thus reducing cooling efficiency.

ABS (Anti-Lock Brake System)
Steering control is sharply reduced when wheels lock. The solution to wheel lock-up (to avoid skidding on slippery surfaces) has been to pump the brake pedal. An Anti-lock Brake System can automatically pump the brakes up to 18 times per second, four times faster than is humanly possible, so it more effectively reduces wheel lock-up. ABS also makes possible selective braking. Only the brake that is locking up is pumped; the other brakes continue to deliver maximum braking power for enhanced steering and braking control. ABS is available on 240SX and Maxima.

Anti-Sway Bar
(See: Stabilizer Bar)

Automatic Choke
A movable valve in the carburetor that automatically reduces the volume of air available to the engine, thus enriching the fuel mixture during starting and warm-up, depending on the engine temperature.

Automatic Locking Front Hubs
Found in some four-wheel drive vehicles, this allows the driver to engage, or "lock," the front axle hubs without leaving the vehicle.

Automatic Seat Belts
Typically a two-point restraint belt which pulls into place automatically once the driver or passenger is seated and the vehicle door is closed. The Sentra Sport Coupes, 240SX and Maxima system include an automatic shoulder belt and a manual lap belt.

Automatic Temperature Control
A combined heater/air conditioning system which automatically balances the amount of hot and cold air required to bring and maintain the interior of a car to a preset temperature.

Automatic Transmission
This feature allows changing of gears and reversing direction without using a foot-operated clutch. Most Nissan models are available with an automatic transmission as optional equipment. They are known for their smooth shifting.

Auxiliary Lighting
This refers to any additional driving, fog or spot lights fitted to the car and used in conjunction with the existing high and low beam headlights.

Axle
A shaft on which a wheel revolves or which revolves with the wheel. Also, a solid beam that connects the two rear wheels of the car. These structures support the vehicle and in some cases transmit torque to the drive wheels.

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