During sentencing, the court heard Yu was driving erratically before he hit Pakura. He blamed his lack of control on a bad reaction to medication.
But Judge Brooke Gibson said Yu drove erratically and at speed for "a prolonged period".
"That continued even after you hit the victim. You travelled on for another 15 minutes and as erratic as it had been before," said Judge Brooke Gibson.
"You then failed to negotiate a bend and nearly hit other cars, so you did nothing after [hitting Pakura] to moderate your driving.
"Prison can be the only proper response."
Yu pleaded guilty in May to killing the 16-year-old and was charged with dangerous driving causing death, failing to stop and ascertain injury or death after a crash and dangerous driving.
With tears streaming down her face, Jacob's mother Esther Pakura today said they have yet to come to terms with the family's loss.
"It sucks that Jacob's life has been taken. His legacy was stolen, it only lasted 16 years, nine months and 12 days," Newshub reported.
"The way his life taken was hateful."
Yu is a Chinese national but has been a New Zealand resident for nine years.
He has prior convictions for dangerous driving and driving with excess breath alcohol.
Judge Gibson acknowledged a prison sentence would impose hardship on his wife and two young children, but stressed Yu needed to take responsibility for his actions.
Yu was also disqualified from driving for four years.