I-Beam: A steel beam that is shaped like the letter "I" when you look at the cross section
Ice Scraper: A small plastic hand-held implement for scraping frost and ice away from windshields and windows. A CD disc does the job even better because it always keeps its edge. Some ice scrapers are located at the end of a brush stick.
Idiot Lights: A colloquial term for the indicator lights on the dashboard which are illuminated when the vehicle is experiencing some problem such as a lack of oil, overheating, failed brakes, low fuel, etc. The alternative is to install gauges which indicate the level of fluids and temperature. A combination of both gauges and lights is ideal.
Idle: The engine speed when the vehicle is not moving. The engine's slowest practical speed.
Idle Mixture: The mixture of air and fuel (usually about 14:1) being fed to the cylinders.
Idling: The action of an engine as it turns over at low speed with minimum throttle.
iFS: independent front suspension
Ignite: To set fire to; to catch fire
Ignition: A process which initiates the combustion of the compressed air/fuel mixture in the combustion chamber. In a spark-ignition engine, the mixture is ignited by an electric spark; in a diesel engine, the self-igniting mixture must be preheated by glow plugs when a cold start is performed.
ignition system: Electrical system devised to produce timed sparks from engine spark plugs. Consisting of a battery, induction coil, capacitor, distributor, spark plugs and relevant switches and wiring
Illuminated: Lit up
Immobile: A vehicle that is unable to move
Imperial Gallon: A quantity of 4.546 liters. Also called "UK gallon." It is 20% larger than a US gallon
Industrial Tire: A heavy duty tire for use on forklifts, lowbed trailers, etc.
Inflate: To fill with air.
Inject: To introduce a fluid (into something) under pressure
Inner tube: A doughnut-shaped rubber or latex air chamber which normally is inserted into a non-tubeless tire to hold pressurized air. It contains an air valve to inflate the tube.
Insignia: the symbol a company uses - i.e. Ford's blue oval, Chevrolet's Bowtie, Oldsmobile's rocket, Cadillac's wreath, and the Chrysler - Dodge - Plymouth's pentastar, etc.
Instrument Panel: The panel below the windshield which accommodates the instruments and controls. Also called dash, dashboard, or fascia
Insulate: To cover with non-conducting material, so as to prevent the transmission of heat, electricity, or sound
Insulation: [1] Any material which does not conduct electricity. It is used to prevent the flow or leakage of an electrical conductor.
[2] Any material which does not readily conduct heat. Used to keep heat or cold out of something.
[3] The process of insulating.
Insurance: A plan which a motorist can purchase for his vehicle which will offset the repair costs of a vehicle which has been involved in an accident. Some plans are offered by a government agency while others are run by independent agencies. All plans offer the basic coverage of property damage and public liability. Others offer extra benefits which cover glass damage, theft, vandalism, etc.
Insurance Premium: A regular payment for an insurance policy
Int: Abbreviation for "interior."
intake manifold: tubing attached to the engine through which the air/fuel mixture reaches the cylinder
Interior: The inside of a vehicle
Interior Light: The courtesy light which illuminates when the doors are opened or when an interior switch is activated.
Interior Light Post: There are two types of switches which turn on the interior lights: One is located on the door posts and is activated when the door is opened or closed. The other is found on the dash and may be incorporated into the headlight switch.
Interior Mirror : The rear-view mirror located centrally near the top of the windshield.
Intermediate Car: A designation no longer used because even "full-size cars" are now about the size of what was the compact car. In 1970, for instance, a Chevrolet Impala was a full-size car, a Chevelle was an intermediate, a Nova was a compact. When cars smaller than the Nova came out (i.e., Chevette), they were called sub-compacts.
Intermittent: Not constant but occurring at intervals.
Intersection: A road junction.
Iron: [1] A colloquial term for any automobile.
[2] A metal used for making steel.
[3] A tire lever or tire iron.
[4] A soldering iron.
iRS: independent rear suspension