For DWI, operating a motor vehicle on a public vehicular area while “APPRECIABLY IMPAIRED” means evidence the driver’s mental or physical faculties were noticeable impaired.
Mental faculties mean the ability to think clearly, understand your situation and communicate. Physical faculties mean the ability to show coordinated movement.
A blood alcohol concentration of 0.08 can prove guilt. Evidence of sobriety (clear speech, safe driving, coordination, etc.,) can disprove guilt.
Performing the field sobriety tests just provides more evidence of impairment so refuse to do these tests and ask to speak to a lawyer.