pasadena_commut
05-22-2008, 11:42 AM
Does the P5's torque converter unlock when the accelerator is released? I don't mean after the car coasts down to the speed at the low end of the hysteresis curve shown in the service manual, but immediately, at any speed.
I have noticed that there is a faint high pitched sound like a turbine spinning up when I take my foot off the gas at speeds where the TC should have been locked, but well above the speed the service manual says it will unlock at. If so, this would in part explain the much better gas mileage cars get when using cruise control, if the cruise control's equivalent of "coasting" actually applies .00001 accelerator, so that the TC doesn't unlock.
I have noticed that there is a faint high pitched sound like a turbine spinning up when I take my foot off the gas at speeds where the TC should have been locked, but well above the speed the service manual says it will unlock at. If so, this would in part explain the much better gas mileage cars get when using cruise control, if the cruise control's equivalent of "coasting" actually applies .00001 accelerator, so that the TC doesn't unlock.