People are shocked when they find out the answer to this question in my office, but yes, you certainly can be arrested and convicted for driving with less than a .08, whether that's a breath test or a blood draw.
In Oregon a person commits the offense of driving while under the influence of intoxicants if the person drives a vehicle while the person:
(a)Has 0.08 percent or more by weight of alcohol in the blood of the person as shown by chemical analysis of the breath or blood of the person...or, (b)Is under the influence of intoxicating liquor, a controlled substance or an inhalant
So you can be arrested for having a .08 or more Blood Alcohol Content (BAC), or you can be "under the influence." A jury would be instructed that to find the defendant was under the influence, they must find that the defendant's physical or mental faculties were adversely affected by the use of intoxicating liquor to a noticeable or perceptible degree.
In short, the state only needs to prove that someone was noticeably or perceptibly impaired, for them to be guilty of a DUI. The state would say that some people are already impaired well before a .08 BAC.
So people can be arrested and convicted of DUII for having under a .08 BAC. But that doesn't mean that they should be. If you or someone you know was arrested for DUII, but you were the below the legal limit, you may need a Portland, Oregon Criminal Defense attorney, give me a call. Anyone that says that you can't get a DUI when your Blood Alcohol Content was under a .08, is wrong.