I can recall in 1993-1995, when Tibs started introducing aircon
buses to the existing NAC bus services.
The OAC Nissan UD RCNs were first introduced in early 1993 and
service 854 was the 1st bus service to be converted to PAC
status.
After which the wider EDS buses (which were the Hispano MB0405s)
made its first mass appearance on service 851.
1995-1997 marked a major Tibs revamp year whereby mass fleets of
new Tibs buses (OAC and NAC MB0405s, Scania L113 Striders, DAF WAs
in 1995) were bought in to replace most of the NAC fleets (regos
from TIB1E to TIB2xx series). It was also a time where Tibs took
over Bt Panjang and Jalan Kayu services. Took a lot of joyrides on
those OAC MB0405s on different routes those days.
In 1997 Tibs introduced bendy bus MB0405Gs. Remembered services
like 82, 160, 176, 812, 851, 856, 912, 913, 960 which got them for
a start. Joyrided them on services 160 and 851 by then. More Habit
bendies were bought in during 2000, whereby more services were
introduced with bendies.
Hmmm... still remember that my first ride on an air-conditioned
public bus was a Mercedes MB O405 on one of the Yishun trunk routes
in 1994 or 1995.
I also remembered the old route 857, which used a full
complement of OAC Nissan Diesel U31RCNs. When was it
introduced?
As for the TIBS Jalan Kayu routes, I still remember seeing a
mostly Scania L113CRL fleet on it, but - on at least one occassion
- a Mercedes MB O405 was deployed. Still remembered seeing that
bus, which I associated more with places like Yishun and Woodlands,
along Lorong 6 Toa Payoh, which looked really out of place to
me.
And the MB O405Gs - I still remember regularly riding them on
route 812 to Yishun Swimming Complex in my childhood days in the
late 1990's; at that time, it was still quite a novelty, and people
called it a "long bus" and things like that 
.
