- PACS
- Priority Assessment of Chemical Substances
- PAG
- Polyalkylene Glycol
- PAH
- Poly Aromatic Hydrocarbon
- PAI
- Peak Area Increase
- PAJ
- Petroleum Association of Japan
- PAO
- Polyalphaolefins
- PBT
- Persistent, Bio-accumulative and Toxic
- PBTVCC
- PBT Value Chain Collaboration team
- PC-
- API Categories for Diesel Engines (prior to introduction)
- PCA
- Polycyclic Aromatic
- PCD
- Passenger Car Diesel
- PCEO
- Passenger Car Engine Oil
- PCEOCP
- Passenger Car Engine Oil Classification Panel
- PCMO
- Passenger Car Motor Oil
- PCV
- Positive Crankcase Ventilation
- PDA
- Premium Diesel Additive
- PDSC
- Pressure Differential Scanning Calorimetry
- PEV
- Plug-in Electric Vehicles and Pure Electric Vehicles
- PFI
- Port Fuel Injection
- PIB
- Polyisobutene
- PIO
- Poly Internal Olefin
- PM
- Particulate Matter
- PMA
- Polymethacrylate
- PME
- Palm Oil Methyl Ester
- PMx
- Particulate Matter with particle size below x microns
- PNA
- Polynuclear Aromatic
- POE
- Polyolester
- POP
- Persistent Organic Pollutant
- PPD
- Pour Point Depressant
- PTF
- Power Transmission Fluid
- PTFE
- Polytetrafluoroethylene
- PTO
- Power Takeoff
- PVD
- Physical Vapour Definition
- PVL
- Passenger Vehicle Lubricant