A numeric rating of gasoline’s resistance to detonation (premature ignition). The higher the rating, the higher the percentage of isooctane and therefore the greater the resistance to detonation offered by the fuel. High octane (above 91) is usually worthwhile only if the manufacturer specifically recommends it. Octane is actually a hydrocarbon(C8H18). Don't use a higher-octane gas than necessary.

The odometer measures how many miles are on your vehicle.

Vehicle intended for operation on unmade surfaces or rough terrain (i.e. for construction or agriculture).

The unit used to measure the resistance of conductor-to-electrical flow. One ohm is the amount of resistance that limits current flow to one ampere in a circuit with one volt of pressure.

An instrument used for measuring the resistance, in ohms, in an electrical circuit.

(e.g. 10W-30) Engine oil comes in various ratings SAE 5W-30, 10W-30, 10W-40, etc. For example, a 10W-30 rated oil will flow like a light SAE 10-weight oil at low temperatures. The W signifies that it is a winter rated oil. The 30 designation means that at engine operating temperatures, the oil will behave like a heavier SAE 30-weight oil. Low viscosity at colder temperature allows the oil to circulate more quickly and protect vital engine parts. Higher oil viscosity at elevated temperatures prevents direct metal-to-metal contact.

The oil filter removes most particles and contaminates from your engine's oil to protect your engine's internal moving parts.

The oil pan is where the oil in your engine is stored.

The oil pressure sensor measures the pressure at which your engine's oil is flowing. If the pressure becomes too high or too low, the oil pressure sensor sends a signal to the vehicle's oil pressure warning light. If you see this light turn on, pull over as soon as possible and shut off your engine. Have your car towed to a service facility to have the problem checked by a technician.

An engine-driven pump that delivers oil, under pressure, to the engine's moving parts.

The lowermost piston ring that scrapes off excess oil from the cylinder walls and returns it to the oil pan via vents in the ring and piston.

Oil that is not derived from raw petroleum. Synthetic oil has superior engine protection properties compared to conventional mineral oil. Synthetic oil costs 3-5 times more than mineral oil.

A unit that monitors the Electric Control Unit and system responses for errors during normal vehicle operations. When the vehicle is serviced, this information on the errors can be down loaded and displayed to the service personnel which will facilitate the trouble shooting process.

The responsiveness and feel of the steering when the wheel is approximately centered. In a car with good on-center feel, the steering wheel tends to return to center when slightly deflected, assisting straight-line stability.

A lease in which the lessor is not responsible for the value of a vehicle when the lease is done. Under this arrangement the lessee is responsible for the difference between the current actual market value at the end of the lease and the residual value. Also known as a 'finance' lease.

A technique in which the steering wheel is turned in the direction away from where the car is turning. Opposite lock is used to control a car when it is oversteering and its tail is swinging wide.

See Four-Stroke Cycle

The shaft which transmits torque from a device, such as a transmission.

The situation where maximum global prodution of automobiles exceeds the total global demand for automobiles.

A small auxiliary gearbox that provides an additional gear ratio. It causes the drive shaft to turn faster than the engine crankshaft or 'overdrive' it. Overdrive gears are used in most modern transmissions because they reduce engine rpm and improve fuel economy at highway speeds. It is engaged manually when under way. It has a transmission ratio below 11. For instance, a manual transmission fifth gear ratio could be 0.701. The overdrive feature saves fuel and, because the engine runs slower, engine wear and noise are reduced.