Toyota Vehicle Glossary Terms
Toyota Vehicle Glossary Terms
Toyota Vehicle Glossary Terms
In a vehicle with this feature (including all Toyotas with power door locks), only the driver's door is unlocked when the
key is turned in that door's lock. A second turn unlocks the other doors. This provides extra security in situations where
a driver desires to open only one door, yet also allows the convenience of easily unlocking doors for all passengers.
2WD
2-Wheel Drive. Also see Front Wheel Drive or Rear Wheel Drive.
4WD on Demand
Allows the driver to go from 2-wheel drive to 4-wheel drive and back while the vehicle is in motion, automatically
locking the front hubs at speeds up to 62 mph. The driver needs only to turn a dial or push a button to engage 4-wheel
drive; it is not necessary to stop the vehicle.
4WD-i
4-Wheel Drive with intelligence (Highlander Hybrid) This innovative electric 4WD-i system employs a separate 50-kw
(68-hp) electric motor (MGR) at the rear that provides up to 96 lb.-ft. of additional drive torque as required. The system
electronically varies the rear torque output depending on driving conditions.
A
Top
Access Cab
2 front full-opening front-hinged and 2 rear-hinged rearward-opening rear access doors with stationary rear windows
and small rear seats.
Accessories
Like options, these are features that don't come standard with a certain model, but are installed usually by the dealer.
You can sometimes ask the dealer to add an accessory to a vehicle on hand.
Aerodynamic Drag
Basically wind resistance, aerodynamic drag is expressed by a measurement called coefficient of drag (Cd). A lower
number means an automobile cuts through wind more efficiently, resulting in better fuel economy and lower wind noise.
Air/fuel mixture
The ratio by weight of the air and fuel in an engine's cylinder.
Alignment
Referring to a vehicle's wheel alignment, it is the proper adjustment of a vehicle that uses the front and rear suspension
for camber, toe, caster and ride height.
Alternator
The part of the vehicle's electrical system that converts mechanical energy from a drive belt into electrical energy to
operate the ignition and electrical accessories, and to charge the battery when needed.
AMCI-Certified Testing
AMCI-Certified testing, comparably equipped 4WD vehicles with optional larger V8s, 4-door cabs and 6' beds,
Automotive News Full-Sized Pickup segmentation.
Amount Financed
The agreed-upon sale price of a vehicle plus any charges for taxes, title, license fees, service contracts and insurance -
less any down payment and/or net trade-in allowance. This is the amount which is subject to finance charges.
A-pillar
The front pillar of a vehicle that supports the windshield and the front of the roof.
Approach angle
The angle between the ground and a line running from the tire to the front bumper (as viewed from the side). Indicates
how steep a ramp a vehicle can negotiate without touching the surface. In off-road driving, provides a good indication of
a vehicle's ability to climb over rocks without damaging the front of the vehicles body or chassis.
Assist Grips
Handles mounted on the inside of a vehicle. They provide a convenient place to grab and obtain leverage for entering
and exiting the vehicle.
AT-PZEV
Advanced Technology Partial Zero Emission Vehicle produce extremely low levels of hydrocarbons (HC) and oxides of
nitrogen (NOx)), emissions that contribute to the formation of smog.
AT
(A/T) Automatic Transmission.
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 vehicle.) Axles help support the vehicle and, in some cases, transmit torque to the drive wheels.
Axle Ratio
The number of times the driveshaft rotates to turn the axle shaft one rotation. For example, if the driveshaft gear had 10
teeth and the axle shaft gear had 30 teeth, the driveshaft gear would have to turn three times to turn the axle shaft gear
once. This translates to a ratio of three-to-one (3:1).
B
Top
Balance Shafts
Balance shafts are small, weighted shafts - similar to a camshaft - inside the engine block. Two balance shafts rotate in
opposite directions from each other at twice the crankshaft speed to help "cancel out" engine vibration. Balance shafts
are most common to 4-cylinder engines to help reduce noise, vibration and harshness (NVH) inherent in this engine
design.
Ball Joint
A flexible joint consisting of a ball in a socket. It is used primarily in the front suspension because of its wide range of
motion.
Battery
An electrochemical device that converts chemical energy into electrical energy. Typical automotive batteries supply the
source of power for cranking the engine and also the electrical energy for the ignition system.
Beltline
The line that runs along the bottom edge of the vehicle's glass area and contributes to the vehicle's styling and visual
appeal.
Bluetooth®
Bluetooth® |1| is a wireless technology that enables connectivity between two or more devices (for example, cell
phone and vehicle) by utilizing a 2.4-GHz radio spectrum that has a range of 10 meters. Bluetooth® allows customers
to use their compatible cell phones hands-free in the vehicle. |1| The phones on this site have been tested for Bluetooth
compatibility with Toyota vehicles. Performance will vary based on phone software version, coverage and your wireless
carrier. Phones are warranted by their manufacturer, not Toyota.
Body-on-frame
A type of vehicle construction in which the body structure is attached to a separate frame. (Toyota 4Runner is an
example of a vehicle that uses this type of construction.)
Bore x Stroke
Bore is the measurement of the diameter of each cylinder, and stroke is the distance the piston travels one-way within
the cylinder. By first determining the area of the cylinder and then multiplying that by the stroke, you can obtain the
displacement for each cylinder. Multiply that by the number of cylinders for the total engine displacement (engine size).
B-pillar
The side or door posts that connect the rocker panel and the roof, providing support for the vehicle's roof.
Brake Caliper
The disc brake component that straddles the rotor and houses the piston(s), cylinder(s) and brake pads. The piston
movement pushes the pad against the rotor to slow or stop the vehicle.
Brake Controller
This feature is the interface between a tow vehicle and electric trailer brakes. It can be inertia-activated or based on time
delay from activation of vehicle brakes. Typically located in the tow vehicles driving compartment with an electrical
line running to the trailer wiring connector. Most require the user to adjust brake gain to compensate for varying trailer
load. A brake controller is necessary when using electric trailer brakes.
Brake Fade
This refers to a reduction of braking effectiveness caused by brake overheating. It can occur during excessively long and
hard brake applications, and can be reduced with ventilated disc brakes.
Bumper-Pull Trailer
Also known as "tag-alongs," these trailers are pulled from a hitch mounted under the rear of a truck (or car) and have a
"tongue" sticking out the front of the box area of the trailer.
C
Top
Cabs
Toyota offers three different cab styles in its pickup trucks: Regular cab with front seats only and two doors. Access Cab
with front seats, small rear seats and four doors (two regular size and two small rear doors). Referred to as an Extended
Cab, SuperCab or King Cab by competitors. Double Cab with full-size front and rear seats and four full-size doors.
Referred to as a Crew Cab, Super Crew or Quad Cab by competitors.
Camber
The outward or inward tilt of the top of a vehicle's tire (as viewed from the front). A tire tipped outward at the top has
positive camber; a tire tipped inward has negative camber.
Camshaft
A shaft in the engine that is driven by gears, belts or chains from the crankshaft. Incorporates a series of cam lobes for
timing the opening and closing of the engine's intake and exhaust valves.
Catalytic converter
A muffler-like device in the exhaust system that helps reduce emissions.
Chassis
The vehicle’s frame with all the operating parts, including the engine, drivetrain, suspension and brakes (but
excluding the body, accessories and trim).
Clutch
Used in a manual transmission, this device connects and disconnects the engine, the transmission and the clutch pedal
that the driver uses to operate it.
Coefficient of drag
The number used to indicate the aerodynamic drag force on a vehicle (a function of exterior styling and the airflow in
and around the vehicle). The higher the number, the greater the drag force a vehicle’s engine must overcome at any
road speed.
Coil Spring
A thick steel wire that has been coiled and heat-treated to form a very strong spring. Commonly used in light truck
suspension systems, coil springs are space-efficient and can vary in stiffness, even within the same spring (i.e., stiff at
the top and not stiff at the bottom). The coil springs on a given vehicle largely define how that truck's ride and handling
will feel.
Combustion chamber
Area located on the top of the cylinders, where the burning of the engine's air/fuel mixture occurs.
Compression Ratio
A measurement of how tightly the air-fuel mixture is compressed or squeezed within the cylinder by the piston. This can
be determined by taking the total volume of the cylinder when the piston is at its lowest point (Bottom Dead Center, or
BDC) and dividing it by the volume when the piston is at its highest point (Top Dead Center, or TDC). In general,
higher compression ratios yield greater power.
Connecting rods
Metal rods that connect the pistons to the crankshaft.
Contact patch
The area where the tires touch the road. Generally, the wider the contact patch, the greater the stability.
Control Arms
A part of the suspension system designed to control wheel movement precisely. It is also known as a wishbone or an A-
arm.
C-pillar
The pillar that supports the back window or the rear portion of the vehicle’s roof.
Crankshaft
The main shaft of the engine that converts the reciprocating motions of the pistons and rods to rotary motion and
delivers it to the front and rear of the engine.
CrewMax
4 door cab with choice of 6 passenger (front bench seat) or 5 passenger (captain chairs) and 4 full-opening front-hinged
doors and fully retractable rear windows and slide/recline 60/40 rear seats.
Cross member
One of several horizontal members in a vehicle's frame that join the side members and add to the vehicle's strength and
stability.
Cruise control
A method of maintaining a pre-set speed as set by the driver.
Crumple Zones
These exist at the front and rear of the vehicle to help absorb the impact of a collision. These pre-stressed areas in the
fender, hood, frame and related body components are designed to deform in a predetermined manner during collision.
Their purpose is to help lessen the force the impact transfers to the passenger compartment. In essence, the crumple zone
of a vehicle is sacrificed to help protect the occupants.
Curb Weight
The weight of an empty vehicle, without cargo and driver and passengers, but including maximum amounts of fuel, oil,
coolant and standard equipment, including the spare tire and tools.
Cylinder
A hollow tube that is machined into the engine block and contains a piston.
D
Top
Daytime Running Lights (DRL)
The daytime running light system activates the low beam headlights at a reduced intensity during daylight to keep the
car highly visible to other vehicles. On some models, a dash-mounted sensor automatically switches between DRLs and
the normal intensity low beams according to the lighting conditions (nighttime, tunnel, etc.). (Note: The DRL system
activates either low beams or high beams - it varies by model.)
Departure angle
This is the angle between the ground and a line running from the rear tire to the rear bumper. Indicates a vehicle's ability
to drive off a ramp or obstacle without damaging the rear of the vehicle. Also see approach angle.
Differential
A gear assembly that allows one driven wheel to turn at a different speed from the wheel on the other end of the axle.
This is necessary since an outside wheel has farther to travel than an inside wheel when turning a corner.
Disc Brake
A disc or rotor is attached to the wheel. A non-moving caliper straddles this disc. When you push the brake pedal, pads
within the caliper squeeze both sides of the disc to slow and stop the wheel. Also see Ventilated Disc Brakes.
Displacement
Refers to the primary measure of an engine's size (volume of air/fuel mixture) and is most often expressed in liters (a
2.0-liter engine displaces 2,000 cubic centimeters).
Distributor
A mechanical component of an ignition system, usually driven by the camshaft, that distributes the electrical power to
the spark plugs. Replaced in most modern vehicles with a distributor-less ignition system.
Distributorless Ignition
Rather than use a mechanical distributor to time spark plug firing, the distributorless Toyota Direct Ignition (TDI)
system places an ignition coil on top of each spark plug (in some cases, two spark plugs share a coil). This eliminates
many wear items and reduces the number of parts in the system as well as the number of high-voltage wires under the
hood.
Double Cab
4 door cab with choice of 6 passenger (front bench seat) or 5 passenger (captain chairs) and 4 full-opening front-hinged
doors and fully retractable rear windows.
Down Payment
The amount of cash or net trade-in allowance applied to reduce the cash sales price of a vehicle. Most retail transactions
require a down payment of 10 to 15 percent of the amount to be financed. However, the required down payment can be
less, depending on your credit standing, ability to repay and other criteria. A down payment helps lower your monthly
payment, as well as establish equity in your vehicle.
Drive configuration
Refers to where the engine is placed in the vehicle and which wheels power the vehicle.
Drive Shaft
The long hollow shaft with universal joints at both ends that carries power from the transmission to the differential in
RWD and 4WD vehicles.
Drivetrain
The system that takes engine output and transfers it to the wheels to produce motion. Consists of the transmission,
transfer unit (if 4-wheel drive), driveshaft(s), differential(s) and axle(s).
Drum brakes
Consist of a rotating drum that is attached to the wheel. Drum brakes are popular because of their self-actuating design.
As the brakes are applied, the centrifugal force of the turning drum tends to apply the brakes harder without requiring
additional pressure from the brake pedal.
Dry Weight
The weight of the tow vehicle without cargo or fluids and, in some cases, trailer. Most RV campers include the trailer in
the dry weight.
E
Top
Early Termination
When a lease is ended by the lessee returning the lease vehicle to the lessor before its scheduled maturity date.
Electrical system
The system that cranks the engine for starting, supplies high voltage to the spark plugs, powers the lights, and operates
other accessories and electrical equipment.
Electronic Brake-force Distribution (EBD)
This system optimizes the braking effort distributed between front and rear axles. Vehicle stability during braking is
improved in conditions that fall short of triggering the ABS. EBD helps minimize stopping distances regardless of load
conditions.
Engine Immobilizer
An ID code stored in a transponder embedded in the ignition key is compared to the ignition transponder. If the codes
match, the immobilizer is deactivated and allows the engine to start. If the codes do not match, the engine will not start.
Engine Mount
Engines (and transmissions) are mounted to a vehicle's frame or sub-frame on top of rubber or fluid-filled rubber
devices.
EPS
Electric Power Steering.
Ergonomics
The science of designing and locating a vehicle's switches, controls, instruments, seats, pedals and steering wheel to
promote comfort and ease of operation on the part of the driver.
ETCS-i
Electronic Throttle Control System with intelligence.
Exhaust valves
In the combustion process, these valves control the flow of the burnt air/fuel mixture to leave the engine and emerge into
the atmosphere.
F
Top
Force limiters
Front seatbelt safety feature that helps reduce the load of the seatbelt on an occupant’s chest, thereby reducing the
risk of injury from the seatbelt itself.
Frame, Ladder Type
Frame rails are single piece. The rails are boxed under the engine for support, rolled-over C-shape under the cab for
strength and quietness and reinforced under the cargo bed for extra payload support. Crossmembers control twisting and
keep the frame rails in parallel alignment.
Fuel injection
A type of fuel induction system that uses a pump and injectors to pump fuel under pressure into the incoming air stream,
as opposed to a carburetor. In modern engines, electronic fuel injection (EFI) precisely measures the amount of fuel
used, improving drivability, performance, economy and emissions control.
Fuel pump
A device that draws fuel from the fuel tank and delivers it to the fuel injectors.
G
Top
Gas-Filled Shock Absorbers
Containing compressed nitrogen gas, these shocks generally respond more quickly and do not "fatigue" under hard use.
Generator
The part of a vehicle's electrical system that creates direct current.
Global Positioning System (GPS)
Global Positioning System along with the map data DVD are used by the navigation system to help locate a street
address, point of interest or other location programmed into the navigation system.
Ground Clearance
The distance between the lowest point on the vehicle and level ground (measurement points vary from manufacturer to
manufacturer).
H
Top
Halogen Headlamps
Headlamps with special bulbs that provide brighter illumination than conventional bulbs yet last longer and use less
energy. They get their name from the halogen gas inside the bulb.
Heating, Ventilation and Air Conditioning (HVAC)
Heating, Ventilation and Air Conditioning systems.
Hitches
A trailer ball can be installed on a bumper for light loads. A frame-mounted weight-carrying receiver hitch can be used
for moderate loads. A frame-mounted weight-distributing receiver hitch can be used for heavier towing. A fifth-wheel
hitch can be used for fifth-wheel trailering.
Horsepower
The measurement of the ability to do work over time. One horsepower is the amount of energy needed to raise 100
pounds a distance of 330 feet in one minute. Simply put, it is the engine performance rating that helps an engine
maintain and maximize vehicle speeds.
I
Top
Ignition system
The system that provides the spark to ignite the engine's air/fuel mixture. System components may include the battery,
coil, distributor, ignition switch, spark plugs and wiring.
Included Sway
Sway occurs in every conventional trailer system because of the joint between the trailer and tow vehicle. Included sway
refers to the longitudinal axis of the towing vehicle compared to the longitudinal axis of the trailer with an intersection at
the hitch ball.
Independent Suspension
Each wheel of an independent suspension is sprung separately so that a bump affecting one does not affect the others.
Induction system
The system that delivers the air/fuel mixture to the engine's cylinders.
In-line engine
An engine configuration in which the pistons are arranged in a straight line.
Intake valves
Valves through which air and fuel enter the combustion chamber.
J
Top
Jam protection
A feature that helps prevent power-operated windows, sliding doors and moonroofs from closing when an object is in
the way.
K
Top
Kaizen
The work process and ethic that involves continuous search for improvement, constantly taking measures to improve
work procedures and equipment. Kaizen often involves utilizing teams of employees who revise their work procedures
and standards round-the-clock to achieve improvements in efficiency, quality and working conditions.
L
Top
LATCH (lower anchor and tethers for children)
Uses lower anchors and tethers in the rear seats to secure child safety seats instead of seatbelts for improved safety and
ease of use.
Leaf Spring
A leaf spring is a flat band of steel, curved into an arc, that usually mounts a solid axle to the vehicle. Most leaf springs
have several bands of steel (a multi-leaf spring). Used in the rear suspension of Toyota trucks, leaf springs are simple,
flexible and very rugged suspension components.
Lease
A contract between lessor and lessee for a specified time period and a specific payment. The title to the vehicle remains
in the name of lessor as owner unless and until the lessee exercises his/her purchase option. Or, in layman's terms: A
contract for a specified time period and a specific payment. The title to the car is in the name of the lessor, unless the
lessee exercises the purchase option to take ownership of the car.
Lessee
You, the customer, who signs a lease with the lessor, and pays for the use of the vehicle according to the regulations of
the lease.
Lessor
The Toyota dealership, and after assignment, the financial institution to which the lease is assigned. The party leasing
the vehicle to the lessee, the actual owner of the vehicle and the lease (i.e., leasing company, dealership or financial
institution).
Locking Differential
Locks rear wheels together for maximum traction when the vehicle is stuck or in extremely slippery conditions. Should
not be used on dry pavement.
MID
Multi-Information Display.
Model Grade
A certain model (Corolla, Avalon, etc.) may come in several varieties or levels of "trim." These are often designated
with letter combinations, like CE or XLE. The model grade is usually based on features that come standard with a
vehicle, though some stylistic differences may also factor in.
Monocoque
A specialized type of unibody construction consisting of thin, carefully joined panels that provide extreme rigidity and
strength. Usually used for sports cars and race cars.
MT
(M/T) Manual Transmission.
Multi-link suspension
A suspension design that uses multiple links to respond more precisely to the terrain and control wheel movement.
Multi-Valve Engine
By using more than the traditional one intake and one exhaust valve (two per cylinder), multiple valves (usually four per
cylinder) increase the flow of the fuel/air mixture into the engine and exhaust gases out of the engine. It also allows a
more central location of the spark plug for more uniform combustion.
N
Top
Naturally Aspirated Engine
Aspiration means breathing. An internal combustion engine that is neither turbocharged nor supercharged. Natural
aspiration gives less power than either turbo- or supercharged engines of the same engine displacement, but generally
operates with better fuel efficiency.
O
Top
Occupant Classification System (OCS)
A front passenger seat equipped with occupant classification sensors that will prevent a front passenger airbag
deployment if the system detects a front passenger of insufficient weight.
Odometer
An instrument that measures and registers the miles and tenths of miles the vehicle has been driven.
Options
These are features that do not come standard with a certain model, but are installed by the factory. Since the vehicles
arrive at the dealer already equipped with options, you don't really choose an option; rather, you choose a vehicle with
the options you like. Not all options are available separately or in all regions. You can contact your Toyota dealer to
help you locate a vehicle that is right for you.
Overdrive
Part of the transmission system that enables the transmission's drive shaft to run faster than the engine itself. This helps
to reduce engine wear and noise, and enhance fuel economy.
Overdrive Transmission
Overdrive provides a final drive ratio of less than 1:1. This allows the engine to operate at lower rpm at highway
cruising speed and provides greater fuel economy, quieter operation, and less wear and tear on the engine. It also helps a
vehicle maximize top-end speed. An overdrive cancel button can be used when hauling heavy loads, climbing hills or
trailer towing to prevent the transmission from repeatedly shifting up and down.
Overhang
Refers to the section of a vehicle's body that protrudes beyond the tires. For off-road driving, it is preferable to have
minimal overhang for easier maneuvering.
Overhead cam
A type of engine design in which the camshaft is located directly above the combustion chamber in the cylinder head
instead of in the engine block. SOHC (single overhead cam) engines have one overhead camshaft operating all the
valves.
P
Top
Park Assist
An advanced computerized system that utilizes sonar sensors to detect obstacles directly behind and at the front and rear
corners of the vehicle, then alerts the driver via an indicator light on the dash and a buzzer tone. (Available on Toyota
Sienna.)
Passive Safety
A vehicle's safety features or equipment that help protect occupants in the event of a collision. (Examples include
crumple zones, seatbelts, airbags, etc.) (See Active Safety.)
Payload
The weight of occupants, equipment and cargo that a truck transports. If the curb weight is increased by adding
components (such as a bigger engine or an automatic transmission), the payload rating will decrease.
Payload Rating
The maximum allowable weight, including occupants, equipment and cargo, a truck can transport - always determined
by the manufacturer. Payload is calculated by subtracting curb weight from GVWR. So, if you increase the curb weight
by adding components (such as a bigger engine or an automatic transmission), the payload rating will decrease.
Piston
Cylindrical casting that moves up and down in the cylinder and pushes the engine’s air/fuel mixture in or out while
transmitting energy to the crankshaft.
Powertrain
Consists of the engine, transmission and final drive of a vehicle.
Privacy Glass
A deeply-tinted rear and side window glass that helps keep the sun's rays out of the passenger cabin and provides an
added measure of occupant privacy.
Purchase
To purchase a vehicle is to outright buy it with a cash payment (possibly financed) and assume total ownership of it
once all payments are made.
Purchase Option
An option in a lease which allows the lessee to purchase the vehicle at the end of the lease term for a specified price.
R
Top
Rack-and-Pinion Steering
Consists of a round pinion gear attached to the steering shaft, and a flat bar with gear teeth cut into it, called the rack.
The rack and pinion mesh at a point between the front wheels. As the steering wheel is turned, the shaft from the
steering column turns the pinion gear, forcing the rack either right or left along a horizontal plane. The rack is linked to
the wheels via tie rods, which push and pull the wheels to steer them. In general, rack-and-pinion steering is precise and
responsive.
Radiator
A device that transfers heat from the liquid coolant to the atmosphere.
Rebound Spring
The rebound spring helps to smooth vehicle ride on rough surfaces by restraining the elongation of the suspension.
Recirculating-ball steering
A highly durable steering design in which the turning forces are transmitted through ball bearings from a worm gear on
the steering shift to a toothed metal block, thereby activating the steering linkage.
Regenerative braking
An advanced type of braking system that is found on electric or hybrid vehicles, it works together with an electric motor
to slow the vehicle and, at the same time, recapture the vehicle’s energy to help recharge the hybrid’s battery.
With this type of brake system, the hydraulic brakes usually operate in only the last few moments of braking for great
braking performance and reduced wear on the front brake pads. (Featured on the Toyota Hybrids.)
Regular Cab
2-door cab with choice of bench or captain chair seats.
Residual Value
The lease-end value of the vehicle set at lease inception by the lessor. It's usually calculated as a percentage of the
MSRP. This is a component of the payment calculation.
Retail Contract
A contract representing the time sale of a vehicle to a consumer.
Ring Gear
Ring gear helps distribute the load over a larger area so the gears last longer when towing.
Rocker panels
The panels located on the side of the vehicle below the doors.
RSCA
Side Curtain Airbags have a roll-sensing deployment feature that will inflate the curtain airbags at severe tilt angles, or
in a roll condition.
RSE
Rear-seat DVD entertainment system allows rear-seat passengers to view DVD video separately from the front audio
system. The system can play DVD video, audio CDs, video CDs, CD text or DVD audio. All functions can be controlled
by a remote control unit.
S
Top
Safety Glass (Laminated)
Used in windshields, this glass consists of two panes bonded together with a sheet of plastic sandwiched in between.
This helps keep the windshield together during an impact, reducing injuries from sharp edges.
Scheduled Termination
The end of the lease term, as called for in the lease. It is also referred to as the scheduled maturity date.
Shift by wire
Transmission technology in which shift performance is accomplished electronically rather than mechanically for quieter
performance and reduced maintenance and repairs.
Shock absorbers
A sealed chamber filled with hydraulic fluid that helps the suspension system maintain optimum ride and handling.
Skid plates
Plates located on the underside of a vehicle to protect vital components from damage when driving off road or through
rugged terrain.
Speed-Rated Tires
A designation of the sustained high-speed capability of the tire. Special compounds and construction enable these tires
to withstand the increase in pressure that comes at higher speeds. The speed rating is the letter on the sidewall in the
tire's size (e.g., P205/65HR15, H=130 mph-rated).
Springs
Components that help the suspension deliver optimum ride and handling. Springs vary by design and include leaf
springs, coil springs and torsion bar.
Sprung weight
The portion of a vehicle's weight that is supported by springs (including body, engine, transmission, passengers and
cargo).
Stabilizer Bar
Sometimes called an anti-roll or sway bar, this is a bar or tube that links one side of the suspension to the other. The
stabilizer bar acts as a torsion spring to resist twisting and reduce body roll during hard cornering.
Starter motor
A small electric motor that initially turns the engine during start-up.
Sub-frame
A partial frame that is sometimes bolted to the body of unibody vehicles. A sub-frame can be used to support the engine,
transmission and front suspension instead of having these components connect directly to the main body structure.
SULEV
Super Ultra Low Emission Vehicle meets California Super Ultra Low Emission Vehicle and the Federal emissions
regulations.
Synchronizer
A cone or sleeve friction device that ensures that the gears in a transmission are rotating at the same speed before they
are engaged. This helps reduce gear grinding when shifting.
T
Top
Tachometer
An instrument for measuring and indicating the speed at which the engine crankshaft is turning, as measured in
revolutions per minute (rpm).
Tailored blanks
Pieces of metal that become progressively thicker as they get closer to the passenger compartment in order to absorb the
force of an impact.
Term
The duration of the retail contract/lease agreement, usually expressed in months (e.g., 24 or 36 months).
Tie Rod
Rods that link the pitman arm and the idler arm to transmit lateral motion to the steering knuckle arms.
Tie-Down Hooks
The cargo bed of Tacoma and Tundra pickups features four tie-down hooks located on the inside of the bed. They make
securing loads easy and convenient.
Tire Aspect Ratio
The ratio of the tire section height to section width. The section height is the distance from the rim flange to the tread
surface. Section height and width can be read by looking at a cross section of a tire, like cutting a piece out of a pie.
Tonneau Cover
The tonneau cover is used to conceal cargo. When the cover is pulled out, it keeps items out of the sun and provides
extra security by keeping personal items out of sight.
Torque
A measurement of force by a twisting motion. In an engine, torque is the twisting force at the crankshaft measured in
pound-feet (lb.-ft.). One poundfoot is the force of one pound acting at a right angle at the end of an arm one foot long.
Simply stated, torque is the engine force that gets a vehicle to speed--felt especially at off-line take-off and during
acceleration.
Torque Converter
A specialized fluid coupling between the engine and automatic transmission. The torque converter eliminates a foot-
operated manual clutch. It allows the transmission to be "in gear" at stops and smooth, automatic and controlled take-
offs and gear shifting during acceleration and towing. This system actually has no direct mechanical connection, but
actually uses a rotating "fan" in a fluid to send power to wheels. When the engine turns the fan attached to it, it drives or
turns the fan attached to the transmission, which sends power to the rear wheels.
Torque Multiplication
The effect that gear ratios have on output torque compared to input torque. For example, if there is 100 lb.-ft. of torque
applied to the input gear of a system where the overall ratio is 2:1, the output torque of the system will be multiplied to
200 lb.-ft.
Tow/Haul Mode
Designed to improve driving and engine braking performance when pulling a heavy trailer or hauling a heavy load by
changing the transmission shift programming to hold engine revs longer before upshifting or downshifting.
Towing Capacity
The maximum weight a truck can pull. Towing the maximum weight may require a particular transmission, trailer hitch
or other equipment.
Towing Weight
The total weight of a trailer and its contents, including filled holding tanks.
Trailing Arm
A suspension component consisting of a longitudinal member that pivots from the body at its forward end and has a
wheel hub attached at the other end (the trailing end). It is similar to a semi-trailing arm system except that its pivot axis
is directly perpendicular to the vehicle's longitudinal axis.
Transfer Case
Four-wheel drive vehicles require a system of gears between the front and rear axles to transfer power from the
transmission to those axles. Transfer cases typically have two gear ranges: high and low. Low range is used for extreme
off-road conditions.
Transmission Cooler
An auxiliary cooler that is available to provide extra cooling for automatic transmission fluid. Lower temperatures equal
longer transmission life.
Tread
1. The outside band of rubber bonded to a tire. The tread is the portion of the tire that contacts the road surface. 2.
Sometimes this term is also interchanged with track.
Tripmeter
An instrument that can be used to measure the distance between specific points or between fill-ups.
U
Top
Ultra Low Emission Vehicle II (ULEV II)
Ultra Low Emission II Vehicle meets California Ultra Low Emission Vehicle II and the Federal Tier 2 Bin 5 emissions
regulations.
Unibody
The floor pan of a vehicle and chassis are connected to form a single structure; there is no separate frame. By welding
all body panels together to form the vehicle's frame, it is possible to build in strength and rigidity with less weight.
Unsprung weight
The weight of vehicle components that are not supported by the springs, including the wheels, tires, brakes and
suspension components.
Used Vehicle
A vehicle that has been previously owned or driven. Also referred to as a pre-owned car.
V
Top
Valet Trunk-Locking System
A locking system with two different keys. One key can only open the doors and operate the ignition. The second key
opens all locks, including those for the glove box and trunk or rear hatch, and operates the ignition. The purpose is to
provide a valet with a key that operates the ignition, but does not unlock the storage compartments. On cars with folding
seatbacks, this locking system also includes special seat latches to help keep the contents of the trunk or hatch secure.
Valvetrain
A collection of components that enables the valves to operate, including the camshaft(s) and all related drive
components.
Variable Valve Timing and Lift with intelligence (VVTL-i)
Based on the VVT-i system, the VVTL-i system has adopted a cam changeover mechanism that varies the amount of lift
of the intake and exhaust valves while the engine is operating at high speeds. In addition to achieving higher engine
speeds and higher outputs, this system enables the valve timing to be optimally set, resulting in improved fuel economy.
When the engine is operating in the low- to mid-speed range, the low- and medium-speed cams of the camshafts operate
to move the two valves via the rocker arms. Then, when the engine is operating in the high-speed range, the signals from
the sensors cause the engine's control module (ECM) to change the hydraulic passage of the oil control valve (for the
variable valve lift), thus changing to the operation of the high-speed cams. Now the lift of the intake and exhaust valves
increases, allowing the introduction of a greater volume of air-fuel mixture, as well as the discharge of a greater volume
of exhaust gases. As a result, the engine operates at higher speeds and higher outputs when the engine is under more
strain.
V-type engine
An engine configuration in which the cylinders are laid out in a V formation.
W
Top
Weight-Carrying Hitch
This hitch is engineered to carry all of the tongue weight of the trailer.
Weight-Distributing Hitch
This hitch, which often includes a sway bar, allows most of the trailer's tongue weight to be transferred to the tow
vehicle's frame (through the hitch receiver). The total load is distributed to all the axles of the truck and trailer.
Wheelbase
The horizontal distance from the center of the vehicle's front wheel to the center of the rear wheel.