The trooper was on top of the Land Rover providing machine gun cover
A coroner is asking the government why an untested Land Rover was used in a patrol in which a Devon Territorial Army soldier died in Afghanistan.
Jack Sadler, 21, of Exmouth was unlawfully killed when when his vehicle hit a landmine in Afghanistan in 2007, an inquest ruled.
His father Ian said Land Rovers were inappropriate for land mine areas.
The Ministry of Defence (MoD) said later types of Land Rovers offered better protection.
Trooper Sadler was a sentry on a reconnaissance patrol when the vehicle hit the mine.
The inquest heard that the WMIK type Land Rover had not been tested for protection against landmines.
Darren Salter, deputy coroner for Exeter and greater Devon, said he would be asking Defence Secretary Bob Ainsworth why such a light vehicle had been used in the patrol.
The MoD said later types of Land Rovers used in Afghanistan offered better protection.
It said safety of personnel was "a prime concern" and £10bn of new equipment had been delivered to the forces in the past three years, including more than £1bn for new vehicles.
Mr Salter said that it was not clear if there would have been a different outcome if Trooper Sadler had been in an updated vehicle.
He said he also got the impression there were insufficient numbers of helicopters to allow equipment to be moved around.
Using them to move men and equipment around would allow convoys to be smaller, faster and less vulnerable, he added.
After the inquest, Trooper Sadler's father Ian also questioned why the Land Rover had been used.
He said: "There is no place in a mined environment for vehicles without the mine-resistant V-shaped hulls.
"The urgent operational requirement is a purpose-built, mine protected patrol vehicle."
The MoD said in a statement: "Our thoughts and sympathies remain with the family, friends and former colleagues of Trooper Jack Sadler at this difficult time.
"We were deeply saddened by his death and we have noted the Coroner's comments.
"Protection of our troops is of huge importance and we take all appropriate measures to minimise the risks through provision of the best equipment, training and procedures to meet our operational commitments.
"We are keen to learn lessons and we await the Coroner's letter to which we will respond fully."
Trooper Sadler, who had studied for a degree in war studies at King's College in London, was a reservist with London's Honourable Artillery Company.
He was providing machine gun cover on the Land Rover, during a reconnaissance patrol checking routes for an impending operation in Helmand Province on 4 December 2007.
The convoy encountered a suspected group of Taliban militants on motorcycles and changed its direction to prevent an attack.
The vehicle was crossing a dried river bed, known as a wadi, when it hit the mine, the inquest at County Hall in Exeter heard.
Trooper Sadler died from multiple injuries, including to his head, neck and lower limbs.