Thanks for the comments. Dealer appt tomorrow. I hope I won't get the normal run around!

Good luck!
 

One solution for this problem, I read in the past, is to disconnect the batery for a few minutes; reconnect it again and slowly accelerating up to cruise speed. Don't know if it helps though...
Let me know if your problem was fixed in any way.
Good luck my friend.

Well, as I expected the dealer couldn't figure it out. So back to square one! Hopefully we'll get a few more comments here in the future with possible resolutions.

I have a 2007 Accent and I believe there is a problem with the transmission. When driving and you let off the gas the cars slows down as if I was lightly pressing the brakes. So I decided to drive about 40 MPH and shift the car into neutral and the car coasts good. If the car is in drive it drags. Seems to be in the transmission because it has no drag in neutral. Gas mileage is terrible, about 150 miles per tank. Does anyone know the cause? Just got the car a month ago.

All automatics do that. Are you sure you're in Drive and not 2nd or 3rd gear?

OH Yea, Positive I am in drive. I know all automatics have a slight drag but this is way more than that. you literally get lunged forward when you let off the gas. This is too excessive of a drag. I have worked on thousands of autos and never had I experienced this before. I have to say I am very experienced but I have only worked on 3 transmission in my life. By the time I reach 1,000 years old I should know it all, LOL.