In Texas, the law provides for a DUI charge as well as a DWI charge.
DUI
A dui charge is for a person under 21 with "any detectable amount of alcohol" in their system. This could be a recent sip if admitted to. Many times law enforcement will not test the driver. This could be to the drivers detriment if in fact no alcohol is in the drivers system.
DWI
Almost any aged driver can be charged with a DWI. This can be charged in two ways. ".08 blood alcohol" or " the loss of normal and/or physical faculties"
