The terminology associated with drunk driving can be confusing. Many states either use Driving While Impaired or Driving Under the Influence. However, Oklahoma distinguishes between the two charges.
A DWI is a lesser charge than a DUI, and sometimes it will not result in any criminal charges filed against you.
A DWI occurs when you have a blood alcohol test showing your level is at least 0.05 but not over 0.08. The legal limit in the state is 0.08, so you are technically below that limit. However, if an officer has proof that your blood alcohol content is high enough that it is impacting your ability to drive safely, then you could face a criminal charge.
A DUI is a criminal charge because it occurs if your BAC is 0.08 or higher. You are breaking the law and will face consequences. The type of charge and the potential penalties will depend on the circumstances of your situation.
Also, note that a DUI is possible for substances other than alcohol that are in your system. While there is no way to measure drugs in the same way as alcohol, the law does not permit any drugs in your system that will impair your ability to drive safely, so you could face a DUI.
A DWI in Oklahoma is not as severe as a DUI. However, it could present the possibility of a criminal charge, even if you are not over the legal BAC limit, and therefore, could become as serious as a DUI.