The short answer is – it depends.  Factors to consider are: jurisdiction of arrest, law enforcement agency of arrest, number of drinks.  Generalizations are a dangerous thing and there are exceptions.

The basic rule of thumb in a DUI case is that a DUI with a “state administered” breath or blood test is harder to win at trial than a case without a test.  This is true simply because the “Legal Limit” is amorphous, constantly changing number.  In the 1980’s, it was 0.12. In the 1990’s, it was 0.10.  Since 1997, it has been 0.08.

Drinking and Driving did not get more dangerous.  Rather, the DUI lobby got more powerful, the limit was tied to federal highway funds, and DUI bills are cheap political capital especially for “conservatives.” So much for “State’s Rights.” No one sees them self as a potential DUI driver and certainly not the typical voter.  What is “DUI – less safe” is generally well above 0.08 and maybe as high 0.15.  I have had clients that could stand on one foot for more than 30 seconds well above .15 and they were clearly not “less safe” (or incapable of driving safely – the legal equivalent of “less safe”) to drive.

Some good ideas are:

1. Don’t take the eye test commonly referred to as the HGN test.  It rarely helps you.
2. Speak in short, concise sentences, be clear, and speak only when absolutely necessary.  Remember you are probably being both filmed and recorded during the entire process.  No rambling diatribes or life stories.  If  you have alcohol on your breath you are probably going to jail regardless.  Start preparing for trial from the beginning.  The police are simply getting ready for trial.
3. If you can avoid it don’t refuse the one leg stand and walk and turn.  It rarely looks innocent to refuse everything. Make the police look unreasonable. Try not to look unreasonable.  However, only do the fields evaluations if you have good balance generally, are athletic, and are not noticeably unbalanced from alcohol.  If you are really drunk, don’t try the tests.  You can not pass field evaluations. Field evaluations are measured in degrees of failure.
4. You can take the small hand held breath test offered before arrest.  It is not admissible as a numerical result only positive or negative for alcohol. You have probably admitted drinking anyway.  Many police will let you go if you blow under 0.08 legal limt on the handheld, pre-arrest breath test.
5. Ask lot of questions: Why do you want me to take field evaluations if I promise not to drive anymore, you must have a reasonable doubt?  What happens if I below under the legal limit? Will you let me go? Am I going to jail?  Can I speak with a lawyer? What happens if I refuse the test?  Can I have an additional blood test and breath test from my own doctor?
6. Don’t blow into the post arrest, cash register sized breath machine or give blood at the hospital, jail, police station or DUI Recreational Vehicle if you want to win your DUI at trial.  However, you may lose your license for a year if you refuse.  It is not automatic if you request a hearing within ten days of your arrest.  If this is your 2nd DUI in ten years or you are under 21 years of age, or the officer is accusing you of driving under legal or illegal drugs always refuse.
7. Don’t tell the police about all the prescription medication your are taking.  Prescription pills can equal  a DUI.  It is no defense that you are following doctors orders.
8. Call a DUI lawyer immediately.  Beware of attorney’s quoting low fees.  Low fees mean pleas.  Attorneys charge by the hour.  Less money equals less time.  We handle a large volume of DUIs and take advantage of economies of scale to offer top quality legal representation at a reasonable price.  We think justice should be affordable and offer payment plans to those without access to capital but with a job and established credit.