Warm up stage question
 

I drive a Lexus HS250h. It's starting to get very cold here and after the car has been parked outside all day, the HSD system acts differently. Normally, when the coolant reaches 139deg, the ICE shuts down when you lift off the gas pedal. Additionally, when the coolant gets to 157deg, it will transition from Stage 3 to Stage 4 when you stop for 10 seconds. The past few days I haven't been able to get the ICE to shut down when I lift off the gas and couldn't get it to transition from S3 to S4 until the coolant temp is approx 188-190. Ambient temp is something like 25deg or lower when this happens. Has anybody experienced anything like this with their HSD system (HS250h, Prius or TCH)?

I know they changed the warm up cycle on the 2010 Prius so its easier to get to S4. I believe you don't have to come to a complete stop for a few seconds anymore. I still have to do this with my 04. However, I don't notice any difference in winter or summer. Coolant temp is coolant temp and with minor exception it works the same all the time.