Systems and methods for enhanced or improved oil recovery includes injecting a Y-Grade NGL enhanced oil recovery fluid through an injection well into a hydrocarbon bearing reservoir to mobilize and displace hydrocarbons. The Y-Grade NGL enhanced oil recovery fluid comprises an unfractionated hydrocarbon mixture. Simultaneously and/or subsequently, a mobility control fluid is injected into the hydrocarbon bearing formation. Hydrocarbons from the hydrocarbon bearing reservoir are produced through a production well or the same injection well.