my manual states that on a cold start the engine should rev up to 2500-3000 RPM for 20 seconds then fall back down.

mazda states that on a cold start the engine should rev up to 1500 RPM for "a few" seconds then fall back down.

which is correct?

 

In nuetral it will go up to 3000. if you start it in 1st it will goto 1500. unless someone removed your AWS.

 

From reading I understand that it's not great for the car to do the accelerated warm up...if you start in neutral you can settle the idle by blipping the throttle just a bit and it will bring the idle down.