Is it because you city driving most of the time plus waiting with air-con for prolong period regularly?
hmmm dont think so leh.. Normally, i always drive from katong to tampines - PIE (drive my gf home) then back to sim drive - PIE (home) leh.
friday when pak tor>> i also go at most city hall or pasir ris niah.....
soi will say it is mainly 50% CT and HW.
for my air con is 25 degree , fan level 1 most of the time.
dont think this is the cause rite??