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

The diesel retail-wholesale spread is $1.627 a gallon right now, up about 52 cents over the past 30 days. The spread is the gap between what a station pays at the rack and what it charges at the pump. It is wider today than it has been through most of the last month. If you are selling diesel, your per-gallon margin has room in it that was not there in early September.

The reason is that the pump ran ahead of the barrel. Diesel is $6.382, up 14.0% over 30 days and near the top of its range, which tops out at $6.529. Gasoline is $4.603, up 9.4% and all but pinned to its 30-day high of $4.628. Brent crude is $99.81 and up only 5.5% over the same stretch. Product prices climbed roughly two to three times faster than the crude that feeds them, and that difference shows up in the street spread. Refiners caught the same move: the 3:2:1 crack is $64.26, up $1.22 over 30 days and still widening.

The thing worth watching is runs. Refinery utilization is 92.5%, down 5.6% over the past 30 days and sitting below the middle of its range. Lower runs mean less product coming out of the plants, and if utilization keeps sliding into the fall maintenance stretch, supply could tighten enough to keep diesel and the street margin firm for a while longer. Natural gas storage is nearly full at 3,351, so the pressure in this market is on the liquids side, not gas.

For now the read is simple. Both pump products are near their 30-day highs, your diesel margin is close to its widest in a month, and the barrel underneath it has moved far less.