A curious observation

Hey Guys, just wanted your opinion on something. I notice that when ever I press the accelerator a bit hard and the RPM goes to the 2500 - 4000 range, my Tucson seems to jerk as if its not getting enough air or something and not continue a smooth accelaration.

I wanted your opinion or guess on what it might be so that before I go to Hyundai I sort of have an inkling on what it might be..

Hope you guys have an idea, or have experienced the same..

Thanks