How to change the type of JIT I want to use

I am trying to figure out how I can configure the type of JIT that I want to use.

Let's say I know that there are 3 types of JIT (Pre, Econo and Normal). But you have the following curious questions.

• What is the default JIT that .NET works with on a deployment server?

• Do we have the flexibility to change the settings for using pre or econo if this is normal by default. If so, where can I change this?

Not sure if this parameter is in the machine.config file or something like that?