 Our Kia developed a severe pinging issue running regular gas especially with the ECO mode on.The Kia Forum website states that Kia is running a series of ecm ( engine control computer ) software patches to solve this issue.Many people on that forum have had the patches done and these patches have largely only helped for a few weeks before the bad pinging came back.I finally decided that I didn't want to destroy my engine no matter how 'great' the Kia warranty supposedly is.I started using PREMIUM - NAME BRAND GAS AND TURNED THE ECO MODE OFF.****Shell Nitro premium gas is THE BEST GAS FOR THIS KIA.BETTER YET BUY A TOYOTA AND LEAVE THIS BRAND TO THE IDIOTS WHO DON'T READ THIS REVIEW!THIS CAR IS COMPLETE FUBAR!ENGINE LIGHTS SINCE TWENTY THOUSAND MILES-RUNNING LIKE A PERSON HAVING A SEIZURE HALF THE TIME.NEVER HAD ANY PROBLEMS LIKE THIS WITH HONDAS,NISSANS OR TOYOTAS WE OWNED.NEVER NEVER NEVER WILL WE BUY A KIA EVER AGAIN.IF SOMEONE GAVE US ONE WE'D SELL IT THE NEXT DAY.STAY AWAY FROM KIA!!!!YOU HAVE BEEN WARNED!!!!!After four gas tanks full of this, our Kia is running and shifting better and smoother then it ever did new.more below-