A motorist has pleaded guilty to driving at 172mph on a rural A-road, making him the fastest speeder ever caught in Britain.
Tim Brady, 33, was caught in a random speed check on the A420 near Abingdon, Oxfordshire, driving a £98,000 3.6-litre Porsche 911 Turbo in January this year.
The current highest speed to result in a conviction is 156mph.
In a short appearance at Oxford Crown Court, Brady pleaded guilty to one count of dangerous driving.
His plea of not guilty to one count of aggravated vehicle-taking was accepted by the Crown Prosecution Service and he will be sentenced next month.
Brady, of Harrow, north-west London, resigned from his job at car lease firm Helphire at its Abingdon branch days after police stopped him in the car.
A spokeswoman for road safety charity Brake branded his actions "selfish".
"The idea of someone driving at that speed is horrific. The chances that a person will be able to control a vehicle at that speed if something unexpected happens is slim.
"It is extremely selfish. Nobody has the right to put other people's lives at risk like that."
In 2003, car dealer Jason McAllister was caught doing 156mph in his 3.2-litre BMW M3 in Scotland. He was jailed for five months.
