| L | Liter(s) |
| L4 | Four Cylinder Inline Engine |
| LCD | Liquid Crystal Display |
| LCM | Lighting Control Module |
| LCV | Light Commercial Vehicle |
| LDF | Long Drain Field test (Scania testing standard) |
| LDT | Light Duty Truck |
| LDV | Light Duty Vehicle |
| LED | Light Emitting Diodes |
| LEP | Light Emitting Polymer |
| LEV | Low-Emission Vehicle |
| LHD | Left Hand Drive |
| L/M | Litres Per Minute |
| lm | Lumens |
| LNC | Lean NOX Catalyst |
| LNG | Liquefied Natural Gas |
| LNT | Lean NOX Trap |
| LOA | Linear Alphaolefin |
| LOFI | Lubricant Oil Flow Improver |
| LPA | Low Pressure Accumulator |
| LPG | Liquid Petroleum Gas |
| LPS | Low Pressure Sensor |
| LRG | Lead Replacement Gasoline |
| LS | Limited Slip |
| LSC | Lubricant Standards Committee |
| LSD | Limited Slip Differential |
| LSD | Low Sulfur Diesel |
| LSRD | Low Sulfur Road Diesel |
| LSUV | Luxury Sport Utility Vehicle |
| LTFT | Low Temperature Flow Test |
| LVL | Level |
| LWB | Long Wheel Base |
