most modern cars do it to keep from over spinning the compressor and to help acceleration on smaller less horspower motors like my pt cruiser !!!
2010 2SS/RS M6,kooks 1-7/8 LT'S with hi flow cats,flowmaster american thunder cat back system,ADM performance street c.a.i.and stage 2 blower cam,160 deg. thermostat,mti six shooter shifter,jac fab front license plate bracket and tunnel brace,eibach 1 inch pro kit,custom ADM performance tune,433 rwp 409 tq