M

M = A Volvo Factory Camshaft
M40 = Volvo Manual 4 speed transmission 1962-75
M400 = Volvo Manual 4 speed transmission (B30) 1962-75
M41 = Volvo Manual 4 speed Tansmission with overdrive 1962-75
M410 = Volvo Manual 4 speed Tansmission with overdrive (B30)1962-75
M45 = Volvo Manual Transmission 4 speed, 75+
M46 = Volvo Manual 4 speed Tansmission w/ sep od 1976-94
M47 = Volvo Manual 5 speed Tansmission 87+
M56 = Volvo Manual 5 speed Tansmission 93+
M58 = Volvo Manual 5 speed Tansmission 97+
M59 = Volvo Manual 5 speed Tansmission 96+
M90 = Volvo Manual 5 speed Tansmission HD 94+
maf = mass airflow meter
mag = magnessium
maint = maintence
man = manual, or manifold
mani = manifold
MAP = Manifold Absolute Pressure
MBC = Manual Boost Controller
MC=Master Cylinder (brakes)
MCU = Motronic Control Unit, or Mixture Control Unit (KE-JETRONIC)
mi = miles
min = minimum or minute
mm = millimeter
mnt = mount
M/O = money order
mod(s) = modified or moderator or modular
morkbla = dark blue
MPG = Miles Per Gallon (number of miles divided by gallons used)
MPH = Miles Per Hour
MS = megasquirt
MSD = multiple spark dist, a brand name
ms&s = megasquirt and spark
mvp = a volvo service shop, that used to sell perf. parts