Does the installation of aftermarket parts help fuel economy?

They may, but Hyundai cannot guarantee the effect of aftermarket parts on fuel economy. Additionally, aftermarket parts may use different materials, construction, and specifications than Hyundai Genuine Parts (even though they might specify their part meets or exceeds OEM standards), which may lead to other vehicle related complications. For this reason, Hyundai will only recommend Hyundai Genuine Parts be used on Hyundai vehicles.