Does it have spark plug wires or just Ignition Coils VERY BAD GAS MILAGE

Hello, this may not be reflective of a spark plug or coil or ignition system concern. Fuel consumption is controlled by many factors -- but air / fuel / spark mixture based on information received by the engine's processor is a key part of it. To address your question about the plugs - use Hyundai plugs and coils only. Removing the coils may cause stress to then rubber boots that insulate the coils onto the plug, so coil replacement isn't a bad idea. 110,000 miles is not an insignificant amount of miles -- this car isn't built to survive hundreds of thousands of miles without major efforts. My suggestion would be to instead perform needed engine performance diagnostic testing to see why the economy could be so precipitously poor -- if in fact it's accurately measured. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops