Thanks to only two non-applied clutches — the same
number as the eight - speed — as well as other design features, the 10 - speed automatic has lower friction that contributes to
greater fuel efficiency over GM's six - and eight - speed automatics.
The range of measures here is quite
great; for example, engine
efficiency can be improved by three different kinds of measures, increasing thermodynamic
efficiency, reducing frictional losses and reducing pumping losses (these losses are the energy needed to pump air and
fuel into the cylinders and push out the exhaust) and each kind of measure can be addressed by a
great number of design, material and technology changes.