What is the best way to warm your engine when it is first started? I used to hear that it was best to let it idle for 2-3 minutes before driving. But then I heard that using that method produces a build up of something that doesn't get burned of when the engine isn't hot. So instead I have been letting it idle for about 30 seconds and then driving it without reving over 2000rpm until the engine temperature rises withing normal operating range. Do you have any ideas on which method is best?