On a recent trip to the Gatlinburg Tennessee area my travels included a climb up "Black Mountain" at Old Fort on I-40. This climb consists of a mile or two of solid uphill grade at @ 55MPH. At the beginning of the grade my oil temp was logged at 238F with coolant at 224F.(Dashawk) After a mile or so of WOT in 6Th gear on the grade the oil was at 215F and the coolant was 212F !!!!! GM has some very interesting engine management going on here. I believe that this is part of their economy regimen. I understand that the ECM has control of the coolant "thermostat". Maybe it has some control of the engine oil heat exchanger too? Another thing that this automobile does in the name of economy: The alternator is modulated by engine load. If the vehicle is decelerating or coasting in gear the alternator charges to about 14VDC. If the drive-train is loaded the alternator charges less with the battery voltage sometimes dropping as low as 12.6VDC. So there is a very small hybrid effect in that the vehicles battery is charged more during deceleration. In essence the vehicles alternator is providing some braking effect during deceleration. I am liking this car more and more for it's engineering prowess and economy. 2011 Chevy Cruze ECO 1.4 6MT. Mild hypermiling regularly yields >50MPG on the highway (calculated and indicated). Rickey.