The parents of a Central Otago teenager say they had previously treated the drink-driver who killed him as family.

Scott David Millar was jailed for three years and 10 months by Justice Nation when he appeared in the High Court at Dunedin this afternoon, after pleading guilty to manslaughter of Ravineel Avikash Sharma and reckless driving causing injury.

The 19-year-old also offered to pay $20,000 to the family of his victim, which was accepted "with some angst".

Justice Nation told the defendant that he would be forever indebted to the Sharma family.

"You owe it to them to make something of your life after your prison sentence finishes and to make sure what you did can never happen again," he said.

"Do not let prison mark you for life."

Mr Sharma, his 19-year-old passenger, died almost instantly when Millar rolled his car down a steep bank in Alexandra after a sustained period of rash driving on August 10 last year.

A family friend of the victim, Andrea Krsinic, read a statement on their behalf.

The Sharmas moved to New Zealand from Fiji more than 12 years ago and said they were left broken-hearted by the tragedy.

"Broken into so many pieces we'll never be able to put them back together," Mrs Krsinic said.

The Sharmas were also stung by the lack of contrition from Millar, the court heard.

"Scott, Ravineel was your friend as well," they wrote.

"You were welcomed into our home and treated as family. You and your family's silence at the time of death hurt us deeply."

Defence counsel Russell Checketts said the pair had been close through secondary school and their friendship had continued when they left.

They were drinking with others at a commercial garage in Chicago St on the night in question.

Court documents revealed Millar did at least one "road-cone beer bong", where the orange plastic item was used as a funnel.

Hayden Crawley was offered a ride home and at 11.45pm the trio departed.

The Sharma family from Alexandria: Rear, Ratnesh Sharma and Santa Sharma and their sons (front) Prashneel Sharma (left) and Ravineel Sharma. (Photo / Supplied)

Millar was described by witnesses as "too drunk to drive" and Mr Crawley queried the direction the defendant was travelling when he sped off in the opposite direction to his home.

He was told by Millar they were taking "the long way home".

Judge Nation told the defendant: "You drove off on a totally unnecessary joyride. Presumably you thought it would be fun".

The court was told that Miller almost immediately lost control of his car, sliding through an intersection and mounting a footpath.

Without checking the damage, he again accelerated away, reaching speeds of up to 120kmh in a 50kmh zone.

Both passengers asked the driver to slow down as they hit the open road but he would not, the court heard.

Mr Crawley noticed the speedometer showed Millar's Nissan was travelling at or beyond 180kmh.

After performing "donuts", the recklessness continued as he drove off down Coates Rd.

Millar used the handbrake to try and "drift" round a right-hand bend, but lost control. The car rolled down a steep bank and came to a violent halt when it collided with a pine tree.

Mr Sharma sustained severe head and neck injuries, which killed him "almost immediately", the court was told.

Millar also suffered a serious head injury, while Mr Crawley managed to climb out of the wreckage to get help.

Scott Millar was jailed for three years and 10 months. (Photo / Supplied)

The defendant was airlifted to Dunedin Hospital where he was put in an induced coma. He was discharged after three weeks and had no recollection of the events.

"With the way you drove your car, it was effectively a lethal weapon," Justice Nation said.

"You drove as though you did not care what risks there were for your passengers or anyone else who might have been in your path that night."

The Sharmas said their Hindu faith dictated a year of mourning over the death of Ravineel and several trips to Fiji, which had incurred costs of more than $16,000, and prohibited them from celebrating birthdays or Christmas.

Since the death, they had not eaten meals at the family table.

"It is too painful to see an empty chair."

Millar's parents, Maxine and David, said they wanted to speak out to try and stop the devastation they and the Sharmas were experiencing.

They said the consequences of the crash had been "horrendous" and begged young people to look after each other and make better decisions: to not drive drunk, to not get into a car with a drunk driver, and to take the keys off people who may drive drunk.

"If we can stop one more time of this happening, if we can stop one silly spur-of-the-moment bad choice and save another young person for their family, then speaking up will be worth it," Mrs Millar said.

Mr and Mrs Millar said their son was being strongly supported by family and friends.