I lose acceleration to vehicle at the lower end shifting of transmission between first and send gears.

To almost all above, mentioning problems with acceleration, stalling, engine light comming on, black smoke from the rear (on diesel), bad fuel economy. READ THIS !!! I have during the past 3 months experienced all of the above, replacing part after part, believing I had resolved the problem. But it always comes back, the stalling, the engine light etc. I have replaced the rail sensor, the mass air flow sensor, the in tank fuel pump, the filters and even the turbo. But still no god. And yesteday was a breakthrouh.......for probably the third time, I opened the cover under the rear seat to access the fuel pump, and found lots of dirt in the diesel. Of course, the filter was clogged, which I lately have replaced 2 times in less than 10 tanks. So I drained the tank, and noticed a sort of layer of paint comming loose, from the tank wall. Thinking WTF ! Called my local dealer today, and they tell me that this had actually been an issue on some Santa Fe's, Tucson's and one H1. It appears that some sort of alloy inside the tank disolves in time, resulting in huge problems of course, and a need for a new tank. Check this on your car, if you are experiencing some of the same symptoms. In my opinion, this is for sure a production faliure, and Hyundai Corp. shoud deal with the cost of replacing the tank with a new one. I will for sure put up a fight with my local dealer, cause this is absolutely ridiculous ! If they say this is normal, than why is it not in the service manual, that the tank need replacing every for example 100 000 km ??!!! Worth noticing that gas and diesel models run tha same tank and pumps, but they differ acording to year. (Mine is a -05 2.0 CRDI.) Hope this will help some of you that have had the problem re-appear, like I have several times. Let me know, and good luck :-)

Posted the above answer that we found on Edmunds blog. Seems to make sense and people everywhere with Hyundai vehicles having the same issues. Seems Hyundai used the wrong metals in their gas tank that react with the gas by creating a corrosion layer that flakes off and clogs the fuel filter. We are looking at replacing the entire gas tank in my daughter's Hyundai that she recently bought. Not too happy. Google the phrase "Hyundai Tucson loss of acceleration alloy clogging fuel filter" and read the forums. Enlightening and the only answer, and makes sense, is posted on the forum. This needs to be complained about aggressively to Hyundai and a recall as seems inherent and a safety issue/flaw in their design. Good luck! I am in P.C. too, daughter in Chicago. Your post made me laugh, so wanted you to get an answer!

We I have only had my 2017 Tucson 7 months and it lost power today. I will have to wait until Monday; since it happen over the weekend. Keeping fingers crossed that nothing major.

I have a 2017 Tucson and have had issues with it since the second day from picking it up. I keep getting the run around that its the way the new transmission is now. What a bunch of BS.

I own a 2015 Tucson which I bought brand new and pretty much since the day of purchase have experienced some sort of acceleration issue. Until just last week when my engine gave out on me found out it was the crankshaft. Thankfully Hyundai offers the 10 yr - 100,000 mile warranty on it if you are the original owner. To all that experience similar issues I recommend mentioning that to your Hyundai mechanic.