Natural Gas

[TrojanMan60]

A coworker recently told me about the ability to add a Natural Gas tank to your car. He said it helps save on gas money, improve fuel economy, etc. Just wondering if anyone can verify this information? Also, has anyone installed something like this? Is it a manual switch in between the two tanks or is it automatic?
I have lots of questions, so any help is appreciated!

 

[Biohazard]

Can't resist.
I have plenty of natural gas. Helps with the hvac system when it's cold out. Also subsidizes the heated seats