If you are talking about driving along on the highway, mashing the accelerator, and having the transmission drop down to the next lower gear, then that's correct. It's supposed to do that. All vehicles with a standard multi-gear transmission will do that. It allows the engine to operate at a higher speed. The faster the engine speed, generally the more horsepower it produces. It also changes the ratio of engine speed to wheel speed. The faster the engine is going in relationship to the tires, the more torque, or pulling power is applied at the wheel. This combination allows the vehicle to increase speed faster. If you're on the highway and need to pass someone, you don't want to take forever doing it. That becomes a safety issue. You will also see the same thing happen when pulling heavy loads or going up hills too. It gets the engine into an optimal operating zone to maximize horsepower and torque.