You may still undergo chemical testing or even be arrested, but remember that your attorney will be able to build a better defense if you refrain from saying anything to the authorities that could help them build a DWI case against you.
Any form of admission, no matter how irrelevant it may seem, can and will be used against you later on. Even a response as simple as, “I had one beer with my dinner” can give the officer enough cause to further investigate the matter. Without any admission, the officer may only pursue a DUI arrest based on your driving or behavior after the traffic stop.
Of course, as already stated, there will always be drivers who choose to be talkative with the police at a DWI stop. Again, this is very understandable considering the stress and anxiety involved with being pulled over by a police officer. However, even so, it is best to only answer the specific question in which you are asked by the officer. Again, if the officer is clearly asking for what could be considered an incriminating statement (i.e. how much have you had to drink tonight?), it is best to tell the officer that you are invoking your right to remain silent. Lastly, if you are already under arrest, the officer must read you the Miranda Warning prior to asking incriminating questions.
Also, keep in mind that any admission to consuming alcohol prior to driving may give the officer cause to for further investigate which could include having you perform field sobriety test. These tests are further used to help the officer establish whether he or she has probable cause to place you under arrest for DWI.
Always remember that a DUI stop, the worst thing you can do is to lie. It will greatly damage your credibility, and make you look bad in front of the jury and judge.
Everything you say at a DWI stop can bring about a potential set of consequences, and may depend on the officer’s mood and personality, as well as how much you’ve actually had to drink. If your blood alcohol level is over the legal limit, there’s nothing you can really do to keep the officer from arresting you for DWI. However, your choice of words and actions may be able to help your DWI case later on. Whether or not you are over the legal BAC limit, it is important to remain courteous to the officer, as doing so will ensure that you receive the best treatment possible.
Additional Source: http://www.motorists.org/dui/traffic-stop.