The ASA said support for women was fair and accurate
The ASA was called in after complaints about an advert from a Cardiff-based insurance company.
The poster, from Admiral Insurance Servicess Diamond Car Insurance, features a man having his hair coloured at a salon, and states: "Some men will try anything to get cheaper car insurance.
It continues: "Diamond only do car insurance for women because women are better drivers."
Passers-by complained to the ASA that the advert was not corroborated by evidence that women were better behind the wheel.
Claim 'proved'
But the advertising industry's self-regulatory body has now ruled the claim was fair and accurate, proving what women have suspected - and men dreaded - all along.
In defence, Admiral offered insurance statistics which, the company claimed, showed women are better drivers because they make fewer, smaller claims.
'Acceptable' claim
The ASA adjudication read: "In the context of the advertisement, readers were likely to interpret the claim to mean that women had fewer accidents and made fewer claims.
"The advertisers had substantiated the interpretation of the claim which was acceptable."
In 1998, a survey from the Automobile Association found men drive faster and break the law more often than their female counterparts, and are more likely to be killed.
Men found one retort in the report, however - women drivers were twice as likely to have accidents at junctions than men.
Neither industry figures nor advertising officials, however, are likely to settle one of history's most enduring assaults on reputation - the gender battle is set to continue for a time to come.