It is normal for the RPM to increase a little when put in park or neutral. If the RPM increases by a lot, then you need to adjust your idle speed.
Adjust your idle.
Put the engine into high RPM in neutral or park.
The rpm's are not at a high enough rate when the car is idleing to engage the clutch plate on the compressor. To get the car to blow cold in park simply give it some gas to raise the rpm's. Belinda from Texas
o2 sensor
Pressing on the accelerator increases engine rpm (revolutions per minute) which in turn increases wheel/tire rpm which increases vehicle speed.
No, because the tachometer actually reads the rotation of the engine, not of the wheels and therefore reads about 500 RPM while in park.
Most modern cars have an automatic choke. This richen's up the fuel mixture and also increases the rpm slightly. once the car warms up the auto choke switches off and the rpm drop off.
Gearing down increases the engine's revolutions per minute (RPM) and torque, but decreases the speed of the car. This allows the engine to work at a more efficient RPM range for the desired speed or acceleration.
Should be about 8 or 900 RPM.
senor
In assumption that this question is referring to an automatic transmission a car's engine will not rev over 2800 rpm because when the car automatically shifts as the speed increases that is the usual rpm that the car shifts at. If the car's rpm is getting over 3000 rpm and still not shifting then your transmission is going out and needs to be checked. The autmoatic transmission is what shifts the gears for you. In a manual (shift, clutch) the person needs to shift around 2500 to 3000 rpm. The only reason someone would let the engine rev higher than that for a long period of time while driving manually would be on purpose to burn carbon build up on the pistons.
Mercedes Benz SLK 230's engine will start cutting out at rpm's above 4k if the car is in park. This is a self preservation safety feature.