87 Octane, unless you've installed a turbo. ;]
The 2010 Hyundai Sonata runs on regular unleaded.
The 2005 Hyundai Tucson runs on regular unleaded.
The 2002 Hyundai Elantra runs on regular unleaded.
The 2009 Hyundai Azera runs on regular unleaded.
The 2007 Hyundai Elantra runs on regular unleaded.
The 2002 Hyundai Sonata runs on regular unleaded.
The 2009 Hyundai Sonata runs on regular unleaded.
The 2012 Hyundai Sonata runs on regular unleaded.
The 2011 Hyundai Sonata runs on regular unleaded.
The 2014 Hyundai Sonata runs on regular unleaded.
The 2012 Hyundai Elantra runs on regular unleaded.
The 2013 Hyundai Accent runs on regular unleaded.