Asia’s refining margins for high sulphur fuel oil (HSFO) exceeded one-year highs on Friday, with front-month cracks posting a weekly jump of more than 30%. The 180-cst HSFO/Dubai crack spread climbed to a discount of $4.83 a barrel at the Asia close (0830 GMT), while the 380-cst HSFO/Dubai crack spread edged higher to a discount …