I guess, it will be tough to increase the speed with the stops it has. With a SF tag, 12839 Mail is taking 7:30 mins for 11 halts and this ICE takes 7hrs 55 mins for 25 halts with express tag. For 1st 166kms, itself it has 14 halts, after that for around 280 kms 11 halts. It still takes correct time for its halts i guess. 18463/64 started from VSKP in the beginning. Later it moved to BBS.