Hybridization Ratio
  Some new concepts have also emerged in the past few 
  years, including full hybrid, mild hybrid, and micro hybrid. 
  These concepts are usually related to the power rating of 
  the main electric motor in a HEV. For example, if the HEV 
  contains  a  fairly  large  electric  motor  and  associated 
  batteries,  it  can  be  considered  as  a  full  hybrid.  On  the 
  other hand, if the size of the electric motor is relatively 
  small, then it may be considered as a micro hybrid.
  Typically, a full hybrid should be able to operate 
  the vehicle using the electric motor and battery 
  up to a certain speed limit and drive the vehicle 
  for a certain amount of time. 
  The speed threshold is typically the speed limit in 
  a residential area. The typical power rating of an 
  electric  motor  in  a  full  hybrid  passenger  car  is 
  approximately 50–75 kW.
  The micro hybrid, on the other hand, does not 
  offer the capability to drive the vehicle with the 
  electric motor only. The electric motor is merely 
  for starting and stopping the engine. The typical 
  rating of electric motors used in micro hybrids is 
  less than 10 kW. A mild hybrid is in between a 
  full hybrid and a micro hybrid.
  An effective approach for evaluating HEVs is to 
  use a hybridization ratio to reflect the degree of 
  hybridization of a HEV. 
  In  a  parallel  hybrid,  the  hybridization  ratio  is 
  defined as the ratio of electric power to the total 
  powertrain power. 
  For example, a HEV with a motor rated at 50 kW and 
  an engine rated at 75 kW will have a hybridization 
  ratio of 50/(50+75)kW=40%. 
  A conventional gasoline-powered vehicle will have a 
  0% hybridization ratio and a battery EV will have a 
  hybridization  ratio  of  100%.  A  series  HEV  will  also 
  have a hybridization ratio of 100% due to the fact that 
  the vehicle is capable of being driven in EV mode.