Mark Lundy's vehicle was the subject of evidence given during the trial into the murders of his wife and daughter today.
Lundy, 56, has denied accusations he killed his wife Christine, 38, and 7-year-old daughter Amber in their Palmerston North home on August 30, 2000.
His trial is taking place in the High Court at Wellington in front of Justice Simon France and a jury of five women and seven men.
At the time of the murders Lundy was driving a Ford Fairmont EL.
Consumer experience consultant Glen Smelt, who worked at Ford for the past 25 years, gave evidence via video link from Darwin in Australia today.
He had given police fuel consumption figures based on Australian tests of a similar car to Lundy's, the Ford Fairmont Ghia.
The Crown earlier alleged there were discrepancies relating to the amount of petrol in Lundy's vehicle when he returned to Palmerston North on August 30.
Mr Smelt said fuel consumption depended upon the condition of the road, the weather, mechanical factors and how the car was driven.
Lundy's car was "reasonably well maintained", he said.
Under cross examination by defence lawyer Julie-Anne Kincade, he agreed that one of the major uses of fuel was by heavy accelerating and braking.
The court also heard evidence from former police officer Nigel Withell who performed tests on the vehicle in March 2001.
Mr Withell described attempting to syphon petrol out of the fuel tank and said he was unable to do it without breaking a flap based inside the entry to the fuel tank.
The flap was undamaged before his attempt, but afterwards, Mr Withell said he was able to siphon 20 litres of petrol within about five minutes.
Former Lower Hutt police officer Murray Rei told the court he was tasked to plot car thefts in Petone between July 1, 2000 and February 2001.
There were 58 cases of theft within that time, including two of possible petrol theft, he said.
Under cross examination by defence lawyer Julie-Anne Kincade he agreed that victims of theft did not always report thefts.
By Rebecca Quilliam of NZME. News Service
