If you get pulled over for DWI (DUI), do not do field sobriety tests. Any pre-arrest tests you may be asked to take are not mandatory. You will not lose your license for refusing any such tests. The requirement to take a field sobriety or blood alcohol test only applies after you are arrested. If you refuse at that time, the State will seek to suspend your license.
In asking questions and requesting field sobriety or other testing, an officer is gathering information to determine if there is probable cause for an arrest. By answering questions or performing tests, you may be assisting the officer in developing probable cause. It would be difficult for an officer to gather sufficient evidence for an arrest if the only observations that officer had were of you sitting in your vehicle.
Often the officer will ask the operator to step out of the vehicle which is merely a request. If the officer makes that request, you do not need to comply. If you are ordered out of the vehicle, comply with the officer’s order. The time to challenge the officer’s decision to place you in custody is not as it is happening. A failure to comply can lead to additional charges. If the officer has not developed probable cause to arrest you, a motion to dismiss those charges can be filed.