Published endurance figures assume a constant economy speed, usually 12 knots for these classes. A Pacific deployment could consume several thousand nautical miles reaching the operating area and returning. The fuel left over then had to cover screening turns, submarine responses, and repositioning against air or surface threats. Running at 25 to 37 knots used fuel far faster than the quoted calculation. This gave a destroyer rated for nearly 7,000 nautical miles a much larger combat margin than one rated for about 5,500.
Notable Point · 1:01:30-1:03:10
Why a destroyer's cruising range overstates its combat endurance
A range quoted at 12 knots leaves out the fuel needed to reach a distant Pacific operating area and manoeuvre around a task force at battle speed.