Description / Abstract:
Because of the intense focus on CAFE and fuel emission
standards, optimization of the automobile drivetrain is imperative.
In light of this, component efficiencies have become an important
factor in the drivetrain decision-making process. It has therefore
become necessary to develop a universal standard to judge
transmission efficiency.
This SAE Recommended Practice specifies the dynamometer test
procedure which maps a manual transmissions efficiency. The
document is separated into two parts. The first compares input and
output torque throughout a specified input speed range in order to
determine "in-gear" transmission efficiency. The second procedure
measures parasitic losses experienced while in neutral at nominal
idling speeds and also churning losses while in gear.
The application of this document is intended for passenger car
and light truck.
All references to transmissions throughout this document include
transaxles.