Japan without Singapore's oil reserves

How would Japan fare if it failed to take Singapore and the region's oil supplies?

Japanese naval operations would face serious fuel pressure, while the Allies would retain stocks intended to sustain a major British fleet for roughly a year and a half.

The issue extends beyond Singapore to oil supplies in Malaya, Rangoon, and other captured locations. In this counterfactual, denying those reserves would restrict Japanese ship operations while leaving the Allies a large stockpile. The estimate given for Singapore is enough fuel for roughly eighteen months of operations by fifteen capital ships, forty cruisers, five carriers, and their supporting destroyer and submarine flotillas. This explains why retaining the base would change both sides' naval logistics.