Could Japan have stockpiled enough oil from the 1920s?

What if the Imperial Japanese Navy began building wartime oil stocks in the 1920s?

An earlier start could improve Japan's fuel position, but large imports might attract American suspicion.

Japan already understood its dependence on imported oil, but acted too late to solve the problem. Beginning in the 1920s would give the country more time to accumulate reserves. A slow program might hide inside apparently inefficient consumption, with part of each year's imports quietly entering storage. American suppliers could still notice sustained buying and ask why Japan was building such a large stockpile.