Pretty poor for an MD-11. Twinjets are far more efficient.
But cargo airlines are different. They tend to fly shorter routes, and there are a lot of older planes sold cheap. They don’t work them that hard. They can justify the fuel burn when the acquisition costs are low. FedEx and UPS were operating 727s for decades where they were mostly passenger castoffs. FedEx even developed (and sold) “hush kits” to make them quieter to comply with noise limits.
You can look at the UPS Airlines fleet. Other than the 747-8F, all older planes. I’m hearing all their MD-11 fleet was converted passenger planes. But I suppose they could justify the 747 for their longer routes since they need the range. I’ve heard that they ship stuff like Apple devices directly from the factories in China/India to consumers.
https://en.wikipedia.org/wiki/UPS_Airlines#Current_fleet