Diesel's street margin is near its widest in a month at $1.63 a gallon

The diesel retail-wholesale spread is the gap between what you pay at the rack and what you charge at the pump. It is 1.627 right now, up 0.523 over the past 30 days, 32 cents a gallon wider than it was a month ago. If you move diesel, the money per gallon is better than it has been for weeks, and that is worth checking against your own board before you reprice.

The wholesale side explains part of it. Diesel is 6.382, up 14.0 percent over 30 days, and it is at the 95 percent mark of its 30-day range. Costs climbed hard, retail climbed with them, and retail pulled ahead. Refinery utilization is 92.5, down 5.6 percent over the month and only at the 41 percent mark of its range, so less product is coming out of the plants while demand holds. Tighter supply with firm demand is the usual setup for a wide street margin, and that is what the numbers show today.

Gasoline is doing much the same thing. It is 4.603, up 9.4 percent, and it is at the 99 percent mark of its 30-day range, about as high as it has traded all month. Brent is 102.53, up 6.5 percent, at the 83 percent mark of its range, so the crude underneath both fuels is strong too. The one piece pulling the other way is the 3:2:1 crack spread, which is 60.78 now, down 1.31 over 30 days, so the refiner's take narrowed slightly even as the retailer's widened.

A margin this wide tends to draw competition once a few stations near you notice it, so the spread could narrow if a neighbor cuts to win volume. With utilization low, the wholesale cost may stay firm for a while, which could hold your margin up longer than usual.