Car insurance prices for young women in the UK rose by an average 16.4% in the final quarter of 2012 after EU rules banned setting prices based on gender.
On average, women aged between 17 and 20 who insured themselves as the only driver paid £2,081 for their premiums.
But married females of the same age only saw a quarterly rise of 4.8%, with an average premium of £2,089 for two insured drivers on a car.
At the same time, quoted prices for men aged between 17 and 20 saw an average fall of 10.7% over the same period.
Gareth Kloet, head of car insurance at Confused.com, said: "With the EU gender directive taking effect from December 21, 2012, it's clear to see that the insurance industry has both reacted and prepared for the well documented and anticipated change in legislation during the last quarter.
"As expected, our index shows that women have seen the greatest changes in their insurance premium as insurers prepared for the change in legislation with what is effectively a gender tax on their car insurance premiums.
"We encourage everyone to shop around in order to get the best deals and if you are married, consider car sharing with your partner to benefit from cheaper car insurance premiums."
The figures, from the latest Confused.com/Towers Watson Car Insurance Price Index, also found the average comprehensive car insurance price now stands at £737 - down from £844 in the same quarter in 2011.
The EU Gender Directive came into force on December 21 last year, banning companies from setting prices according to gender.
The ruling, by the European Court of Justice, followed a 10-year legal battle against the proposals by insurers.
More From Sky News