Young women's car insurance premiums have soared by 16% as insurers adjust their prices to comply with new European "gender neutral" rules, a comparison website has found.
Meanwhile, typical quoted prices for young men tumbled by 11% over the last three months of 2012, boosting their chances of being able to afford to get on the road, Confused.com said.
The average price of comprehensive cover for a young woman aged between 17 and 20 rose to £1,986 by the end of December, marking a £279 price hike from three months earlier.
The new rules mean that from December 21, insurers have no longer been able to take someone's gender into account when calculating how much money they should pay and what benefits they should receive.
The rules apply not only to car insurance but also other products where gender has traditionally been taken into account, such as life insurance and retirement products such as annuities.
Young women have traditionally been offered cheaper car insurance than men as their accident rates tend to be lower, leading experts to predict that younger women will be among the worst affected by the changes.
Confused.com's figures also showed that the typical premium for a young male driver dropped to £2,960 by the end of the year, a £354 decrease from three months earlier.
Gareth Kloet, head of car insurance at Confused.com, said: "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.
"On average, males aged 17-20 are now paying £2,960 for their car insurance, compared with £3,829 in the second quarter of 2011, meaning men are now having a greater chance of getting on the road as their premiums come down."
The car insurance index, compiled by Towers Watson, uses quotes submitted on the Confused.com website, taking the average of the best five deals from each quote.