A teenage passenger died after a young driver who was "showing off" by demonstrating how fast he could go crashed into another car.
Dylan Benjamin was driving far too quickly when he tried to take a sharp bend and lost control of his car, slamming into an oncoming vehicle.
Rear-seat passenger Ellie Bryan, 18, died while two other youngsters in the car were badly injured.
Benjamin suffered grave brain injuries and was in an induced coma in hospital for two weeks, Wales Online reports.
Swansea Crown Court heard the 19-year-old's "fatal decision to show off" had devastated lives and caused emotional scars that would last a lifetime.
The court heard the crash happened on the the evening of Saturday, November 16, 2019, on the outskirts of Aberystwyth.
Jim Davis, prosecuting, said Benjamin and Miss Bryan were among a group of friends who met and socialised on Aberystwyth seafront.
By around 10pm Benjamin, Miss Bryan, and two others were sat in his Vauxhall Astra while the fifth friend, Lena Faye Evans, was in her Vauxhall Corsa.
The barrister said Benjamin began "being rude" about Miss Evans and said they should leave her and then a firecracker was thrown at her car.
A short time later Benjamin drove away followed by Miss Evans and the two cars made their way along the seafront and through the town before heading up Penglais hill past the university and out of Aberystwyth.
The court heard witnesses would later describe how the two cars were slowing down and then speeding up as they made their way together out of town.
Davis said at this point someone in Benjamin's car made a comment about Miss Evans being close behind them he responded with words to the effect of: "I will show you how to lose her."
He accelerated away "fiercely" along the A487 towards Commins Coch.
But moments later, at a sharp right-hand bend, Benjamin lost control of his car and smashed with a roadside tree before veering across the carriageway and crashing into an oncoming Audi.
All four people in the Astra were seriously injured in the crash.
Miss Bryan was rushed to Bronglais Hosptial but could not be saved and died the following day.
The driver and passenger of the Audi which Benjamin crashed into were left shocked but uninjured.
The court heard both Benjamin and his front-seat passenger were wearing seat belts but the two female passengers in the back were not.
Mr Davis said the exact speed the Astra had been going at the time of the crash was not known but the speedometer in the crashed car was frozen at 72mph and there was some evidence that some braking had occurred.
A victim impact statement from Miss Bryan's heartbroken mum which was read to court she said her eldest daughter had been at "heart" of their family.
Benjamin, from Bontnewydd, Aberystwyth, Ceredigion, admitted causing death by dangerous driving and two counts of causing serious injury by dangerous driving. He has no previous convictions.
Ian Ibrahim, for Benjamin, described the events of that night and everything that had flowed from them as a "tragedy".
He said Benjamin was "as remorseful as anybody can be" and had written a letter of apology to Miss Bryan's family.
Giving the defendant a one-third discount for his guilty pleas the judge sentenced him to 40 months in prison for causing death by dangerous driving and to 18 months for each of the causing serious injury by dangerous driving charges with all the sentences to run concurrently.
The court heard Lena Faye Evans was acquitted of causing death by dangerous driving and two counts of causing serious injury by dangerous driving.
Dyfed-Powys Police were unable to supply a custody image of Dylan Benjamin.
