Call Mark Thiessen The Texas Trial Attorney at: 713-864-9000br Thiessen Law Firmbr 1221 Studewood St.br Houston, TX 77008br Visit my youtube page for more helpful DWI tips.br br People get a DWI and DUI mixed up all the time here in texas a DUI is driving under the influence thats only for people under the age of 21 that aren't intoxicated. Even if you blow a .04 it doesn't matter in Texas. We have a zero tolerance policy and if you are under the age of 21 you will be charged with a DUI even if you are under the legal limit. DWI is for anybody 0-100 years old. If you are intoxicated they don't care what age you are. If you are over a .08 or have lost your mental or physical faculties then that's DWI.