Adrian Ryder's Ford Sierra spun out of control on the M25 in Essex and struck a 38-ton Sainsbury lorry which then crossed the central reservation, where it was hit by three cars.
The prosecution at Chelmsford Crown Court says Mr Ryder's rear tyres were worn below the legal limit. Mr Ryder denies a specimen charge of causing death by reckless driving.
Mr Ryder, 25, of Bilbrook near Wolverhampton, said that at the time of the accident he had been driving in heavy rain for about 100 miles and 'hadn't experienced any loss of control of any sort'.
He said there was a tremendous amount of spray from lorries and he decided to overtake. As he did so the rear end of his car jolted and the front end spun towards the centre lane. He braked and tried to correct the car but collided with the front offside of the cab of a lorry on the nearside. He then managed to bring his car on to the central reservation.
'I saw the lorry shudder at the point of the impact and then it was following me across the lanes. It passed me on my nearside just before I brought my car to a halt.'
Mr Ryder said before the accident he had been travelling at 35- 40mph and as he pulled out to overtake he accelerated to 50- 60mph. 'I knew I was well within the speed limit,' he said.
Mr Ryder would have lost control of his car even if the tyres were not worn, the jury was told.
Peter Jennings, an accident investigator and forensic scientist, said that even new tyres would aquaplane at speeds above 60mph in water more than 9mm deep.
The court was told how Mr Ryder lost control of his car at 70mph when it aquaplaned on 12mm of water and hit the lorry.
Mr Jennings read out conclusions in his accident report which found Mr Ryder's car was not travelling much faster than the lorry. 'With spray from other vehicles reducing visibility and in nearly dark conditions, it is unlikely that any driver would be able to see the water flowing across the carriageway, nor would he have reason to anticipate it at that location,' he told the jury.
'The probability of Ryder's car aquaplaning was increased because it had wide tyres.'
Those killed in the accident, all from Essex, were: two brothers, Peter and Dennis Greenwood, aged 40 and 42, of Chelmsford; Martin Argent, 36, of Maldon; Danny Miller, 60, of Burnham-on- Crouch, and his son Ian, 34, of Mayland.
The trial continues today.Reuse content