James Kenneth Austin is serving 13 years' jail with a non-parole period of eight years for the manslaughter of mother-of-four Jacqui Purton at a rural property at Campania in Tasmania in 2023.
He pleaded guilty and was sentenced in July but has appealed the length of the sentence on the basis it is manifestly excessive.
Austin, who was initially charged with murder, left Ms Purton to die on the driveway of the property at night after hitting her with a Holden Commodore at 20-30km/h.
He tried to divert police away from the home, before calling an ambulance and telling them someone else had been driving and that they had hit an "unidentified person".
"Your actions were cold blooded, callous and selfish to an extent which is difficult to describe in words," Supreme Court of Tasmania Justice Michael Brett said during sentencing.
It was difficult to imagine a more serious example of manslaughter by culpable negligence, Justice Brett said.
Austin was controlling and violent towards Ms Purton during their on-and-off relationship and was subject to a family violence order stipulating he not abuse or assault her.
In an appeal hearing on Tuesday, Austin's lawyer Kim Baumeler said the sentence was "so far" above other manslaughter sentences.
She said the scenario of the case was not unique and it wasn't unique for people subjected to family violence orders to be in each other's company and for things to "go badly".
"This is obviously terrible offending but to categorise it as the worst is placing weight to the conduct that isn't necessary," she told the Court of Criminal Appeal.
"Without trying to compare apples with oranges, there is offending in the manslaughter offence that have not attracted this sentence."
Crown lawyer Linda Mason said the case was a very serious case of criminal negligence and the family violence order compounded the harm.
"He was intending to cause her fear and harm," she said.
"The steps he took afterwards ... his only concern was for himself."
The Court of Criminal Appeal will deliver a decision at a later date.
Justice Brett ruled Austin drove at Ms Purton to scare her and it was clearly foreseeable that if she didn't move out of the way there was a grave risk to the point of certainty he would run her over.
The court was told Ms Purton went underneath the length of the car and there was no evidence Austin braked before hitting her.
Austin's sentence was backdated to April 2023, making him eligible for parole in 2031.
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