The American Trucking Assns. has reiterated fuel supply concerns associated with the petroleum industry’s switchover to allocate 80% of its diesel supply to ultra low sulfur diesel (ULSD) by June 1.

ULSD is expected to result in a fuel economy loss of up to 1%, while retailing for five cents per gallon more than the low sulfur diesel that’s widely available today.

By Oct. 15 retail outlets must comply with the ULSD rule. In a recent interview with FleetOwner an Oil Price Information Service economist said that after Oct. 15, low sulfur diesel is likely to be more expensive than ULSD. Local supply disruptions will likely bring scattered price spikes, the OPIS official warned.