Adaptive Equipment problems of the 2015 Hyundai Sonata

The car suddenly loses the ability to accelerate making it very stressful to drive as you are not certain when this will happen. At first it is intermittent but eventually it simply stays that way once the issue begins while you are driving, hence the car will have an almost impossible time retaining speed on the highway or accelerating at a light or as you merge onto highways. Changing the driver mode to sport appears to have a positive effect as it causes much more aggressive gear shifting but it then stays in the same gear for too long reaching rps that feel unsafe for the engine itself. This is now the third tie this happens and it is also the more severe manifestation of the problem,. The first time the dealer asserted they were not able to diagnose it but returned the car without the problem. The second time it happened they apologized and said that it was an issue with the engines computer algorithm, that apparently the computer learns from the way in which one drives and so is adaptive but that sometimes it can become corrupted. This third time the dealer told me it would take only a couple of hours to fix but now it has been three days and they have not called me back. They did leave a message that apparently they are ordering parts and will be fixing it. My issue now is that its a third time and it is clear that something in the car is defective and now we are going to be almost completely paranoid of it happening again at a critically dangerous intersection or merge area. We have been lucky so far but it is a family car and I do not feel safe in the car anymore given the repeating nature of this problem and the lack of information out there form the manufacturer as to what exactly is going on.

Since leasing the vechicle on August 1 I constantly complained about the gas mileage which hyandai indicated would be resolved on the following oil change. The oil change bearly effected the mileage efficiency which leads to the second issue when the gas guage shows below a quarter on the tank the cruise control does not work and is also affected in high mountain areas. When I explained these issues to hyandai they said they never heard of it and would sent to the company for further review in the meantime I have a car with the gas guage that does not show exact amounts from fill up to empty makes this car a safety risk that is totally unacceptable not to mention the car is running horrible which suggest other safety features are not working accurately. The dealers look over only suggested other underlying issues exist with this vehicle and is a clear safety hazard.