Air tool questions. CFM vs PSI

[hutch]

If I have a compressor that runs at 5.7cmf at 90psi can I run a tool that is spec'd out at 5.6 at 40psi?  Does it matter if I run a 1/4" hoes vs 1/2" to bring it down ot 40psi?

Not sure how it all works is my point.  I want to paint my own car but dont know if I can run a paint gun off my dewalt 40gal 200PSI 5.7cfm compressor. If I take lots of 5 second breaks or paint it in sections will that help?

[mikepmcs]

Cubic feet per minute (cfm) which equals the volume of air that the compressor supplies to the sprayer or air tool. Larger jobs require higher cfm ratings.

Psi or pounds-per-square-inch rating measures the amount of air pressure generated by the compressor. Tools also have psi ratings, and these must be considered when matching the tool to the compressor.

Stolen from the web.

[400/6/PAC]

Any good paint gun will have it's own regulator and spray a high volume at a low pressure.
You just need an air tank that will hold enough air and recover quickly.
Your best bet is to practice and see how it dose.

[hutch]

Any good paint gun will have it's own regulator and spray a high volume at a low pressure.
You just need an air tank that will hold enough air and recover quickly.
Your best bet is to practice and see how it dose.

Thats good info.  I was thinking I could get a 1/2" hose and regulator to make it work, and then just paint 1/4 of the car at a time.  I am going to play with the hood and trunk first a few times to see.

thanks.