arrest for DUI from 4 years ago

My Husband was arrested on a warrent out of Arizona from 4 years ago. He has pled guilty and his Lawyer is saying the best he can get is 21/2 years his sentencing is on 3/22. he has already been in jail for 4 months how much time will he actually do for a 2 1/2 year sentance.

Did he run someone over or what? That's a mighty long time for a dui.

He was involved in an accident but no one was seriously injured.
They did not file an arrest on him until 2 years later he did not even know he had a warrent because he has been living in Florida he found out there was a warrent in Dec. 2001 and they extridedted him back to Arizona. His Laywer said that the best he could get is 2 1/2 years will he actually do that much time? I have written and so have several other people the Judge about how he has changed his life around since he has left Arizona. He goes for sentencing in March.
They say they are charging him with Aggrivated assault, endagerment and DUI with priors. but they said if they can not find the witnesses to the accident they would drop it to his 3rd DUI. His lawyer came pack with a 2nd plea bargain of 2 1/2 years and he signed.

My guess he'll probably do 12-18 months. Too bad he has already signed 'cause it sure does sound like he has gotten the short end of the stick