Would an oil-first Queen Elizabeth-class design have been more efficient?
Short answerYes; a hull designed around oil could have been more efficient and perhaps achieved a practical 26 knots.
NotesCoal bunkers and oil tanks impose different demands on hull shape and volume. An oil-first design combining Queen Elizabeth length and power with a more efficient Revenge-like hull might have reached a practical speed near 26 knots. The comparison uses about 24 knots as the existing class's practical speed as a group, against a theoretical 25 knots. Two extra practical knots would bring the fast battleships closer to the battlecruisers on both the run south and the run north at Jutland.