The freight rally has raised the premium for West Texas crude from the U.S. to more than $4/bbl against Dubai quotes on a cost-and-freight basis for April delivery from ~$2/bbl last week, traders said, reportedly pushing WTI to a premium of $1/bbl more than Murban crude from the United Arab Emirates - which is somewhat similar to WTI - for delivery to Asia, up from parity or a small discount last week.