Generation matters more than mileage with this compact. The 2011-2015 models earned their troubled reputation through a cascade of PCV valve failures that pressurize the crankcase and blow oil past every seal in reach, valve covers, timing covers, turbo lines all start weeping, turning ownership into a parts-replacement cycle. Coolant systems corrode from the inside out when neglected, and by 100k miles repair bills often exceed resale value. The 2016-2019 redesign fixed most of these gremlins and delivers the comfortable, well-equipped compact GM should have built from the start, but those improved cars are scarce on used lots. Manual transmissions of any year hold up better than automatics. If you're shopping used, a 2017 with 80k miles is a safer bet than a 2013 with 50k, the generation gap is that wide. Skip the first-gen unless you enjoy wrenching or have a trusted mechanic on speed dial.
The Sonata offers sharp styling and premium tech at a price that undercuts the Accord, but the 2011-2019 Theta II engines were catastrophic, seized motors, oil consumption, and rod bearing failures between 60k-100k miles, with dealerships often fighting warranty claims. The 2020 redesign brought fresh looks and the 2022+ SmartStream engines show real improvement, but depreciation still reflects the older models' sins. Walk past anything pre-2020; current-gen buyers get genuine value and a 10-year warranty, but you're betting Hyundai has truly fixed what broke.