There are effeciency classes for induction motors in the UK, the government is trying to get people to upgrade to more effecient motors.
The classes are IE1, IE2 and IE3.
IE1 which is standard for older motors can be as bad as 70%, and IE3 later designs can be as good as 95%, the effeciency also depends on how the motor is loaded, not just the % of max power loading but also the type of load.