Rarely should we need to use the block heaters in Cali unless you lived up in the hills. These engines seem to start fine above 0 degrees F with a healthy injection & GP system. I do agree that using one will significantly decrease cold start engine wear tho. 15w-40 is damn near molasses in cold temps, and using block heater prior to startup will warm up the oil, making it much easier to flow. Matter of fact, I plugged in my block heater when I was ready to fire up my reman engine. Even put a heater underneath oil pan. 2 cranks and it fired up. There's probably nothing worse than startin up a brand new rebuilt engine for the first time in cold weather without heating it up first.