Unburned Hydrocarbons

Some articles on unburned hydrocarbons, unburned:

Wankel Engine - Design - Engineering - Fuel Economy and Emissions
... relatively incomplete combustion of the air-fuel charge, with a larger amount of unburned hydrocarbons released into the exhaust ... paradoxically enriching the air-fuel ratio to the point where the unburned hydrocarbons (HC) in the exhaust would support complete combustion in the thermal reactor while piston-engine cars required ... the extreme that controls the amount of unburned HC in the exhaust is the rotor surface temperature, higher temperatures producing less HC ...