Kangarooing: A colloquial term for moving forward in a succession of sudden jerks as a result of improper use of the clutch, (a characteristic of beginner drivers or those not used to standard shifting)
Kerb weight: (br) British term for "curb weight" -- the weight of a vehicle with fuel, oil, and coolant; but without occupants, luggage, or cargo.
Kerosene: Also spelled "kerosine"

[1] fuel for jet engines
[2] A solvent used to remove grease.

(br) - British term is "paraffin."

Kevlar ®: The brand name of a DuPont™ synthetic fabric that is clothlike in feel and is used in cold outdoor activities (e.g., by bicyclists and motorcyclists).

It is also used in bullet-proof vests and tires. KEVLAR® is used in tires two different ways, for two different purposes: KEVLAR® beads are used on some high performance tires. Replacing the normal wire bead with KEVLAR® saves about 50 grams per tire. KEVLAR®-bead tires have the additional advantage of being foldable, making them popular as emergency spare tires with touring cyclists. KEVLAR®-bead tires are somewhat harder to mount on a rim, and are more likely to blow off than wire-bead tires. They work best on "hook edge" rims. KEVLAR®-belted tires have a layer of KEVLAR® under the tread surface, with the purpose of making the tire more resistant to punctures caused by small sharp objects, such as thorns and glass slivers. KEVLAR®-belted tires have slightly higher rolling resistance, price and weight than corresponding tires without the belt.

key fob: A device to hold keys.
Keyless Entry System: A system which allows you to lock and unlock your vehicle's doors and trunk without using a key. One system is operated by punching a typically five digit code into a calculator-style keypad located on the driver's door; if more than five seconds elapse between button pushes, the system will abort, requiring you to start again. Another system uses a dedicated frequency in a special key fob. Pressing the "lock" button will lock all doors and sound the horn for a very short beep. Pressing the "unlock" button once will unlock only the driver's door; but pressing it twice will unlock all the doors.
kick panel: A vertical panel wall enclosed by several structural members (e.g., the side panel ahead of the A-pillar that extends up to the sides of the bulkhead and is limited by the floorpan at its bottom end)
Kick start: To start a motorcycle engine by kicking a pedal downwards
Kickstarter: A pedal lever and ratchet mechanism for kick starting an engine
Kill switch: A special switch designed to shut off the ignition in case of an emergency.
kilometer: (km) A unit of length. 1 km = 0.6213712 miles (about 5/8 mile); 1 mile = 1.609344 km.

In Canada it is pronounced KILL-oh-mee-ter, but elsewhere it is pronounced kull-LAW-mitt-er. Colloquially it is referred to as a "klik" or "klick"

kilometer per hour: (km/h or kph) A unit of velocity
kit car: car that is assembled (often by the DIY enthusiast) from its constituent parts
knobby tire: On a bicycle or motorcycle, a heavy-duty tire with large rubber knobs spaced relatively far apart to provide traction in wet, muddy terrain.
knock: A general term used to describe various noises occurring in an engine; may be used to describe noises made by loose or worn mechanical parts.
knock off: A single, large wing nut for fastening a wheel to the hub. Easily removed and replaced, it is struck (knocked off) with a mallet on the wings. Also called a "spinner."