Men may say they would stop to help a woman motorist changing a tyre but in reality nearly all drive on by.
When questioned, more than half (55 per cent) of males claimed they would assist a female but tests by the Continental Tyres company showed that 97 per cent failed to help when presented with a real-life chance to play the good samaritan.
Tyre-changing incidents were monitored in five cities - Birmingham, Newcastle-upon-Tyne, Norwich, Cardiff and Bristol.
In Bristol, not one of 726 male drivers stopped to help a woman who was trying to change a tyre.
Just three per cent of men stopped to help in Cardiff, six per cent in Norwich, 10.5 per cent in Birmingham and 15 per cent in Newcastle. All told, of 2,000 vehicles observed, only 32 men offered assistance.
Of those surveyed, 60 per cent of younger people (aged 16-24) - more than any other age group - claimed they would stop to offer help to a stranded female motorist.
However, in reality, the most likely to stop were those aged 40-50, accounting for one third (31 per cent) of all offers of assistance.
Kate Hanson, from Continental Tyres, said: "Although the exercise was a bit of fun, there is an important under-lying safety message for women motorists. If you get into a situation where you need to change a tyre on your car, you cannot always rely on being able to ask for help."