Dear Mr. Thai-Kiwi
Upon checking , please be noted that the actual miles is depends on Airlines flight system to calculate the actual miles
Such as BKK-SIN on SQ operated is calculataed 880 miles and 1,100 for Business class ,
for BKK-SIN on TG operatd is 889 miles and 1,111 for Business class .
Thank you for your kind understanding on this matter .
Best Regards,
Chuthamas T.
Royal Orchid Plus Department