Hmmm. Do you have tonnages? Would be interesting to compare BPs tanker fleet to Japans...
The spreadsheet has all the BP Tankers operated from the formation the company's formation to 1945 and includes some second-hand ships dating back to 1880.
The fleet at the beginning of 1939 consisted of 95 tankers built 1899-1938. Their combined displacement was 617,893 GRT - Average size 6,504 GRT.
This included 21 tankers built 1931-38 with a combined displacement of 166,368 GRT - Average size 7,922 GRT.
The Company acquired 33 tankers 1939-45 inculding Empire ships operated for the Ministry of War Transport. They had a combined displacement of 265,947 GRT - An average size of 8,059 GRT.
Also from Post 64
According to the British Official History on Merchant Shipping and the Demands of War the Japanese only had 47 tankers (over 1,600 GRT) displacing 430,000 GRT. I think that can be increased by at least 50%.
For comparison the British had 420 tankers of 2,977,000 GRT and the Dutch 107 tankers of 540,000 GRT. Interestingly (at least it is to me) the Japanese ships with an average displacement of 9,149 GRT were of considerably larger than the British and Dutch whose average sizes were 7,088 and 5,047 GRT respectively.
Those were the figures at 1939 from Appendix VII. The information reads more clearly as:
Japan - 47 tankers (over 1,600 GRT) displacing 430,000 GRT - average size 9,419 GRT
Netherlands - 107 tankers of 540,000 GRT - average size 5,047 GRT
Great Britain - 420 tankers of 2,977,000 GRT - average size 7,088 GRT
I already had the spreadsheet scanned so here is Appendix VII in full