I bought a Honda Accord LX 2010 model, and I live in Detroit where -10C temperature is an everyday thing. I was advised by my friend to start the engine and let the rpm drop down a bit after which I can start driving the car. So immediately after starting the car it is always in 1500 rpm range. After waiting for a minute or so it drops down to 1200 rpm, after which I start driving it. I just wanted to know: 1. Is it necessary to wait like this for the rpm to drop or am I wasting gas unnecessarily? 2. If it is necessary then how do I know when it is good to start driving the car?
Please note that upon starting the engine, the car is running the front and rear defroster in almost full power, along with the radio.