I see alot of people on the forums talking about how they replaced them. I'm not sure what that is and what it will do so can someone explain because maybe i should do that to my car but i need to know what it is frist.

The thermostat is a device that controls the coolant flow through your engine.
Once your engine coolant reaches a certain temperature, the valve opens to let the coolant flow and it cools your engine.
This one opens at 180 degrees so the coolant flows sooner to keep your engine running cooler.
Someone who knows more please correct me if I'm wrong.

right on. As stated, it opens and closes based on the coolant temp. When it hits a certain magical number, the thermostat opens to allow coolant to flow to the radiator to exchange the heat and keep the engine from overheating.

Stock thermostat is 195*(unless I'm crazy), and changing to a 180* will not really do much aside from opening before your fan(*) turn on.

The fan(*) that pull air through the radiator are set to turn on at temperatures at or slightly above 195* from the factory.

It'* been my understanding that the higher temp thermostat allows you to burn fuel more efficiently. If that'* true or not, I don't know. It sounds good though. The cooler thermostat is generally put into a modified engine to help with removing the extra heat it makes. Typically the computer is reprogrammed to account for the lower temperature thermostat so that the fan(*) turn on at a lower temp, closer to whatever thermostat is used.

NYRangers, That'* correct as written. The 180* thermostat will open when your coolant temp reaches 180* F. Many people here feel this will help the longevity if not the performance (maybe a bit?) of your engine.

This from TECHINFO, under the title First performance mods:

For more info, and tons of threads talking about this, search on this site, using "drilled thermostat".

alright guys thanks alot for all the help this site is really good for helping people glad i can be apart of this website!