Woth modern fuel injection, warming your car up is not needed, and it does more harm than good. My manual says quitw "as soon as you start the car, you should be ready to go" "Under extreme low temprature, the engine should be idled for no more than 15-30 seconds"
I asked valvoline about how much synthetic was really in the blend, they said they couldn't tell, but around 10%, i said that really didn't sound like much, he told me that the blend isn't just 10% synthetic mixed in to a dino, but that it had some other properties that helped it preform better...