And because this car has really K.E.R.S.( look it up on google or wiki)
when pressing the nitro button and hold it, you release an extra kick of power.
I tested it on routeX, With the nitro button pressed, the car is 8 seconds faster to reach topspeed.
used it yesterday with the A-spec expert race.
Without using the nitro button, i got 1st at lap 5.
With the nitro button pressed at every straight part of Tokio R246, I got 1st in lap 4 and got the battery almost fully drained at the end of lap 5

That was fun.