What's a stock Bullitt supposed to idle at after it's been warmed up and it's in regular operating temperature? I turned on the digital tachometer that our cars have, and apparently I'm idling between 690-710. My RPMs needle shows it's at 700, but I guess it's normal for it to jump between 20 RPMs constantly. Anyway, I've heard that the normal idle RPMs is around 800 to 850, is that right? If so, why is mine idling so low?