There's a very good series of videos on Youtube by a lawyer explaining why you should REMAIN SILENT. Perhaps somebody can post a link.
The most convincing point to me was that it isn't even safe to tell the absolute truth. If a credible witness mistakenly contradicts what actually happened, the contradiction alone might reflect badly on you, making it appear that you are lying.
Anything you wish to say can be said AFTER you talk to your attorney. I can't remember if it was the same series of videos which makes it clear that NOTHING you can say is likely to reverse the opinion of an officer who would decide to arrest you if you remain silent.