transmission hesitates from stopped position for about one

I bought a 2009 Hyundai Santa Fe a over a year ago in 2015. I had very low miles and a bargain. I noticed on acceleration that it took about a second for the the transmission to move the car from stopped position. No none has pinpointed it (My Mechanic, dealer mechanic) just said it was annoying. Dealer told me there is no throttle and it was computerized!? Idon,t know enough to check it myself but it doesn,t make sense. It hasn,t got any worse but now I,m reading that other owners are complaining about later models 2010, 2013 Santa Fe,s. that are worse than mine like scarier hesitations. I also had a 2002 Santa Fe which I liked a lot. No hesitation, great car! However I,m getting the same highway mileage as the 2009. I,m thinking maybe this is due to the hesitation problem causing just a slight bit of one to 3 miles per gallon on the highway compared to my 2002 Santa Fe. This car would be terrific if they just find out what this problem is. R.D.