one of the pluses of syn oil is it's ability to "cling" better than petroleum refined oil. This means much less wear and grief on your motor at the all important start up, which as you correctly infered is the worst time for the motor. Another plus of this oil is it's ability to flow more quickly even in cold weather. My procedure is to let the system do it's thing. I have confidence in both the syn oil and BWM engineering. If the weather is really cold, just drive slowly for a block or two. Just my opinion, mind you, but I discourage overreving a cold motor.