I hate to break it to you, but your driver’s ed teacher is telling the truth. You can get a reckless driving ticket for speeding—but the amount you can speed before it’s considered reckless driving varies quite a bit state-to-state.
Generally, the following speeding infractions will run into reckless driving territory:
While driving 10 mph over the limit won’t typically earn you a reckless driving ticket, it can still earn you a regular speeding ticket. The best practice, of course, is to stay focused and always drive at the posted speed limit. Remember—they can’t give you a reckless driving ticket for excessive speeding if you were never speeding in the first place.