- M -

Mass

The measure of the quantity of matter that is contained in a given quantity of solid, liquid, or gas.

Mass Air Flow

Measurement of the volume and density of the air entering the engine.

Mass Airflow Sensor (MAS)

A device found at the inlet of the intake manifold of an electronic fuel-injection system which supplies the computer with input as to the volume of air entering the manifold, using the temperature differential between a heated platinum wire or a plastic film and the passing air, to generate a signal of varying voltage.

Mass Production

The manufacture of a product in large quantities.

Master Control

A primary or main control.

Master Cylinder

A brake-system component having an integral reservoir filled with hydraulic brake fluid where pressure is developed when the driver depresses the brake pedal causing a linkage to move a piston.

Master Kit (MK)

An engine kit that contains crankshaft and camshaft bearings, lifters, oil pump, pistons, rings, gasket set, and core plugs.

Master Leaf

A term used for main leaf, as in a spring.

Mastertech

A Scantool manufactured by the Vetronix corporation.

MAT

Manifold air temperature.

Mat Fabric

A fiberglass fabric with an irregular strand pattern.

Match Bash

Two out of three, or three out of five drag racing events.

Match Race

The same as match bash.

MATCO

A tool manufacturer and supplier to the automotive industry.

Material Expanders

Fillers that are used in the place of active material in a battery; the primary difference between a 3- and 5-year battery.

Material Safety Data Sheet (MSDS)

A sheet required of the product manufacturer by OSHA, containing specific information about hazardous materials to be displayed in any workplace where such materials are used.

Matter

1. Anything that occupies space and possesses mass or weight 2. All things in nature are composed of matter.

Maxi-Fuse

A large, cartridge-type fuse having a higher current-capacity use because they are less likely to cause an underhood fire when overloaded.

Maximum Peak

The highest voltage recorded over a specific time period.

Maxwell's Law

James Clerk Maxwell (1831 - 1879) did revolutionary work in electromagnetism and kinetic theror of gasses. Maxwell showed that a few relatively simple mathematical equations could express the behavior of electric amd magnetic fields and their interrelated nature.