Ken, the CHT value rises very quickly and is normal operating temperature much sooner than the vehicle is allowed to go into electric mode.

I have found my vehicle needs fWT at or above 153 degrees for the first time after startup (after sitting for several hours--not necessary true when one make mulitple short stops as found when one does shopping at different locations) to go into electric mode. This is one reason some of us are using engine block heaters--to enable quicker transition into electric mode. I can keep my vehicle in electric mode until fWT drops to 123 degrees. The vehicle will then require a fWT temperature of 140 degrees or higher for electric mode to return provided SOC is >42%.

There is a sticky thread on the scangauge values you may want to review.

2005 AWD Escape Hybrid
Best Interstate tank trip MPG 39.02 (scangauge II) for 402 miles on I-70, 10.3 gallons used over mostly flat terrain. Aug. 2007

Best Interstate tank trip E30 MPG 34.6 for 271 miles along I-80 in Indiana and Ohio. May 2008

Best multiple road tank trip E30 MPG 36.2 for 202 miles in Southwestern Pa. July 2008.