2008 Hyundai Elantra Response time.

It seems my car doesn't respond very quickly to the gas pedal. Since I got it from the dealership there seems a delay between applying pressure and getting additional motion. Particularly in reverse a slow increase in pedal pressure takes like 2.5 seconds to do anything and when it does it jolts backwards. Is this the draw back of better highway mpg? Anyway to improve this type of thing? My mechanic fixed my rear breaks recently and didn't mention anything about the accelerator so I assume this is the norm.