Knapp CITGO is a convenience store of Knapp Oil Co, INC, a family owned business of Southern Illinois since 1933. Outside of your typical convenience store offerings, we also run monthly specials for snacks, drinks, candy, and beer. We serve up several lunch options of which many come off our very own smoker! Including chicken, hamburgers, pork steaks, pork chops, and more. And most importantly, our staff is next to none!