Why do the rpm rev up when driving but you are acceletrating any higher?

The RPM rev up when driving because of the way your car's transmission works. Essentially, the transmission is responsible for sending power from the engine to the wheels. The transmission's job is to change the RPMs that the engine is sending, so that the wheels can turn at the correct speed. When you accelerate, the transmission increases the RPMs that the engine is sending to the wheels to provide more power. The faster you accelerate, the more the RPMs will increase. This is why you hear the RPM rev up when you are accelerating.