There are many disadvantages of hybrid electric vehicles. First of all, hybrid electric vehicles are not all-electric vehicles. They do require gasoline to drive.
Hybrid electric vehicles use regenerative braking to get their electricity. The gas energy is captured off of the brakes and stored as electricity. All electric vehicles are a much better alternative in terms of cutting down smog. There are several available today.
Hybrid electric vehicles are also inferior to hydrogen fuel cell vehicles. Many automotive companies are working on hydrogen fuel cell vehicles in production now. Very soon Chevy will come out with a hydrogen fuel cell vehicle.
While hybrid electric vehicles are low smog emission vehicles, they do produce emissions. Hydrogen fuel cell vehicles produce water as their emission, making them far superior to hybrid electric vehicles. Or better yet take public transportation in a city that uses hydrogen fuel cell buses.
Although hybrid electric vehicles are readily available, they are a large investment. There are sometimes $10,000 difference in between a hybrid car and a subcompact although the mile per gallon difference could be only a few miles freeway miles. This is an investment that might not be immediately recaptured in gas savings.
Of course, hybrid vehicles are not ideal for freeway drivers. The reason is because hybrid electric vehicles use regenerative breaking. If most of the miles put on the car are on the freeway, there is less braking involved and less regeneration of electricity involved.
Another disadvantage of hybrid electric vehicles is some models are very difficult to obtain. They are heavily advertised and there is a heavy demand. But many automotive manufacturers are using a showroom car to lure customers into the showroom to see a hybrid that there is a long waiting list for. Customers needing a car now and not six months from now end up buying a gas guzzling SUV because the hybrid SUV is not yet readily available.
A large disadvantage of hybrid electric vehicles is they give auto manufacturers a chance to tell the state and federal governments that they are doing something to lower vehicle emissions. Then car manufacturers insist that the government has no reason to bully the manufacturers to make cars with reasonable miles per gallon rates of say 100 miles per gallon. Hybrid cars are a smoke screen for the car manufacturers to pretend they care about the environment.
Finally, hybrid electric vehicles are available only to the most elite car buyers creating a disparity between rich communities and poor communities. Poor cities have drivers creating lots of emissions in old eight cylinder cars while rich cities have rich citizens driving expensive hybrid electric vehicles with low emissions. Probably the biggest disadvantage of hybrid electric vehicles is that they are cost prohibitive to the poor.