im thinking of getting a sports bike as my main form of transportation when i turn 18 ( depends on the age to get a bike license is) i need to know how good they are on gas
All things considered, NO and YES.
Depends on how you ride.
There are more more 'fuel-efficient' bikes available and some of them are fun rides.
Most 'sports' bikes are geared toward speed, after that it's a mixed bag of nuts.