| MAF | Mass Air Flow |
| MAP | Manifold Absolute Pressure |
| MAT | Manifold Air Temperature |
| MB | Mercedes-Benz |
| MCU | Microprocessor Control Unit |
| MDFI | Middle Distillate Flow Improver |
| MDP | Manifold Differential Pressure |
| MECA | Manufacturers of Emission Controls Association |
| MEM | Memory |
| MERCON | Ford ATF specification |
| MFI | Multipoint Fuel Injection |
| MFVM | Multifunctional Viscosity Modifier |
| MIL | Military Specification |
| mm | Millimeter |
| mm³ | Cubic Millimeter(s) |
| MMT | Methylcyclopentadienyl Manganese Tricarbonyl |
| MOC | Mineral Oil Content |
| MON | Motor Octane Number |
| MPa | Mega Pascal |
| MPFI | Multipoint Fuel Injection |
| MPG | Miles Per Gallon |
| ms | Millisecond |
| MSDS | Material Safety Data Sheet |
| MSM | Memory Seat Module |
| MSVA | Magnetic Steering Variable Assist |
| M/T | Manual Transmission/Transaxle |
| MT | Metric Ton |
| MTAC | Multiple Test Acceptance Criteria |
| MTBE | Methyl-T-Butyl Ether |
| MTF | Manual Transmission Fluid |
| MTV | Manifold Tuning Valve |
| MV | Megavolt |
| mV | Millivolt |
| MVEG | Motor Vehicle Emissions Group |
| MVMA | Motor Vehicle Manufacturers Association |
| MVSS | Motor Vehicle Safety Standards |
