2015 HYUNDAI SANT FE LIMITED 3.3L AWD, PURCHASED NEW FROM DEALERSHIP, 129,280 MILES. ROUTINE OIL SERVICE WITH MOBIL 1 SYNTHETIC AND WIX FILTERS SINCE PURCHASED. TRAVELING 75MPH ON I-10 (FLORIDA) WITH CRUISE CONTROL ON. NOT TOWING, TRAVELING STRAIGHT. AS THE VEHICLE STARTED UP A SMALL GRADE IN THE ROAD, THE CRUISE CONTROL SURGED (AS NORMAL TO MAINTAIN VEHICLE SPEED) I HEARD A BANG, CHECK ENGINE LIGHT CAME ON, OIL LIGHT CAME ON, ENGINE DIED IMMEDIATELY. I IMMEDIATELY SHIFTED INTO NEUTRAL AND LOOKED OUT THE PASSENGER WINDOW TO MERGE ONTO THE SHOULDER AND NOTICED AN ORANGE GLOW OUTSIDE (IT WAS NIGHT). ONCE STOPPED, OPENED HOOD AND NOTICED SMELL OF OIL, OIL POOLED IN THE UNDERBODY FAIRING. CHECKED OIL DRAIN PLUG AND FILTER, AS I HAD AN OIL CHANGE 700 MILES PRIOR. BOTH WERE STILL PROPERLY INSTALLED. TOWED TO LOCAL MECHANIC, DIAGNOSIS WAS SEIZED ENGINE. INSPECTED ENGINE BLOCK AND NOTICED FIST SIZED HOLE IN BLOCK (SEE PHOTOS). TOWED TO DEALERSHIP, WAS INFORMED THEY HADN'T SEEN THIS BEFORE ON THIS ENGINE. I INFORMED THEM I CURRENTLY DRIVE A 2001 HYUNDAI ELANTRA WITH 220K MILES ON IT AND HAVE BEEN DRIVING/MAINTAINING CARS FOR 30 YEARS AND I'VE NEVER SEEN THIS BEFORE EITHER. WAS INFORMED THAT THEY SUSPECT IMPROPER OIL MAINTENANCE. OIL AND FILTER BOTH REPLACED EVERY 5000 MILES. ALWAYS MOBILE 1 SYNTHETIC AND WIX (GOOD QUALITY FILTERS/OIL). I SUSPECT HYUNDAI HAS ENGINE RELIABILITY ISSUES. NO PRIOR ENGINE ISSUES NOTICED. NO CHECK ENGINE LIGHTS PRIOR. NO OIL LIGHTS ON PRIOR. WE JUST COMPLET