My Elantra 2011 is consuming 9.3 L per 100 km (combined City and HWY).
That is very bad in my opinion.
Mechanics in Hyundai could not find anything wrong.
They will do road test on their own when weather allows.

I am suspecting that car computer is failing, each time when do some update/tuning on computer, it is even worse.

Your thought is very appreciated. What are my options here ???