3) I plugged in the block heater for 1.5 hours, and when I turned on the car I didn't notice a difference in startup temperature. Temp outside was24 F. Is this normal or abnormal?
You should hear a gentle sizzle as the heater operates. You won't if it's noisy around though. The car should be notably easier to start, and warm up faster. I doubt it would bring the needle off the peg though. It's only a 400W heater. -- Jim