Sales of hybrid cars have soared in the last few months due to rising fuel prices, but a new study suggests that increased fuel economy doesn’t make the investment worthwhile.

According to the study, which was conducted by Santa Monica, California-headquartered TrueCar Inc., an “automotive solutions provider focused on changing how cars are sold,” at 15,000 miles per year and $3.52 per gallon (the national average when the study was published), it would take 14 years to make up for the Toyota Prius’ higher sticker price compared to the (non-hybrid, manual transmission, sans-AC) Hyundai Elantra. Even at $5 per gallon, it would still take a decade for the fuel savings to make up for the up-front cost difference.

Part of the reason hybrids aren’t necessarily the most cost efficient (despite being the most fuel efficient) is because they’re too big. Remember the old Honda Insight? The tiny two-seater of the early 2000s achieved 70-plus MPG, but today’s hybrid versions of old standards like the Toyota Camry and Honda Civic reach only 33 and 41 MPG respectively.

Of course there are other perks to driving a hybrid, well, at least for another few weeks. In California, the sticker program that allows single-occupancy “clean air vehicles” to use carpool lanes will expire on July 1.

Luckily, for those looking for hybrids that could balance out up-front costs sooner, Ford is planning to roll out the C-Max Hybrid which is rumored to fare better than the 41 MPG Fusion Hybrid, and later this year Toyota will offer a smaller version of the Prius called the Prius C, which averages over 50 MPG.