SALEM – A Peabody man who admitted driving drunk for his fifth time may spend up to four and a half years in state prison.Michael J. Rinker, 31, of 30 Keyes Drive, Peabody, pleaded guilty Wednesday to a charge of operating a motor vehicle while under the influence of alcohol, fifth offense, before Salem Superior Court Judge Timothy Q. Feeley.Rinker was sentenced to serve not less than two-and-one-half years and not more than four-and-one-half years in state prison. He has already served 279 days at the Middleton Jail awaiting trial and will now be transferred to the state prison system, where he will be incarcerated until he serves the remainder of his sentence.Had Rinker faced trial, Assistant District Attorney Jennifer Kirshenbaum was set to introduce evidence and testimony to prove that Rinker was driving drunk on the morning of March 25, when he got into a verbal altercation with his former co-worker at the Jiffy Lube on Route 114, on Andover Street in Peabody.Trooper Sean McGarry was at the Jiffy Lube having the oil on his cruiser changed when the manager approached him and asked for assistance.When Rinker saw the trooper approaching, he jumped into a 1999 white Cadillac sedan and took off, ignoring McGarry’s orders to stop.Rinker peeled out of the parking lot, squeaking his tires and driving erratically as he headed east onto Route 114.McGarry ran the license plate of the vehicle and discovered Rinker had an outstanding warrant from Woburn District Court for unlicensed operation.Then McGarry discovered through his investigation that Rinker was driving on a suspended license and had four prior drunken driving convictions in New Hampshire.He obtained Rinker’s telephone number from his former employer, called the number and spoke to Rinker’s girlfriend. He then headed to the apartment complex on Keyes Drive where Rinker had been staying and found the vehicle parked in a handicapped parking space.Rinker was found by the trooper at the apartment complex. McGarry observed a very strong odor of alcohol and appeared to be heavily intoxicated.McGarry administered several sobriety tests, which Rinker failed, before being placed under arrest.Kirshenbaum urged the judge to impose a three- to five-year state prison term based on Rinker’s record dating back to 1999 and his most recent conviction in 2006 out of Belknap Superior Court in New Hampshire.Kirshenbaum pointed out to Feeley that Rinker is only 31 and already had four prior drunken driving offenses before this incident.