There are several questions surrounding U.S. refiners following their fantastic run over the past two years, but the most important one is: Can they keep it up?

On the one hand, coastal refiners like Valero (VLO 0.37%) and Phillips 66 (PSX 0.56%) have the ability to move product to both domestic and international markets, and inland refiners like HollyFrontier (HFC) have access to cheap Canadian oil and other disadvantaged feedstocks. On the other hand, the price difference between domestic and foreign crude is getting smaller by the day, eating into margins.

Which side is right? Check out the debate between the bull -- Fool.com contributor Tyler Crowe -- and the bear -- Motley Fool Energy bureau chief Joel South -- in the video below and find out whether this is still a space worthy of your investment dollars.