Epa can also be used to slow down you RC. Throttle epa that is. I have a 6yr old and a 3 yr old. They like to drive my truck but I wouldn't dare just let them have at it with the 6.5t I have in there. So I'll drop the throttle and brake epa to around 45-50. Gives them a nice smooth throttle response while also making sure they aren't driving it like a rocket. This may not apply to you but thought I would share anyway.