Select a letter to go to the terms beginning with that letter.

HC
Hydrocarbons
HCCI
Homogeneous Charge Compression Ignition
HCFC
Hydrochlorofluorocarbon
HD
Heavy-Duty (vehicle or lubricant)
HDD
Heavy-Duty Diesel
HDDEO
Heavy-Duty Diesel Engine Oil
HDS
Hydrogenated Styrene Diene
HEUI
Hydraulically Actuated Electronically Controlled Unit Injectors
HEV
Hybrid Electric Vehicles
HFC
Hydrofluorocarbon
HFFI
Heavy Fuel Flow Improver
HFO
Heavy Fuel Oil
HFRR
High Frequency Reciprocating Rig
HGO
Heating Gas Oil
HP
Horsepower
HSD
Hydrogenated Styrene Diene
HSDI
High Speed Direct Injection (diesel engine)
HSE
Health, Safety, Environment
HSE (UK)
Health and Safety Executive
HTHS
High Temperature High Shear