I sincerely hope that SMRT does not buy Volvo B12BLEs. This is
because fuel consumption of the Volvo DH12 engine is extremely high
- nearly twice that of the Mercedes-Benz OM 457 hLA or Scania DC9
in city traffic.
As for Euro 4/5 emissions ratings, all major manufacturers already
have offerings that satisfy these ratings.
Mercedes-Benz offers the OC 500 LE in a Euro 4 (optional Euro 5)
rating with a powerful 299PS OM 457 hLA engine using BlueTec SCR
technology. Optionally available, of course, is the M 447 hLAG
natural gas engine which has met Euro 5 standards since it's launch
in 2000, with ratings of 252PS and 326PS.
Volvo offers the B12BLE with the new DH12E engine for Euro 4/5,
again with SCR technology. There is only one rating of this engine
for use in buses and that's 340PS with 1700Nm of torque.
Scania and MAN are using EGR, with the DC9 (230PS, 270PS, and
310PS) and D0836 LUH/D2066 LUH engines respectively. Scania and MAN
also offer Euro 5 natural gas engines with the OC9 G02 (260PS)/OC9
G03 (300PS) and E2876 LUH (310PS) respectively.
Practicality is an issue here. SCR requires the installation of new
urea filling stations at bus depots, whereas EGR increases the
engine's thermal loading. All Euro 4/5 rated buses (whether diesel
or CNG) are significantly heavier and more complex than Euro 2/3
buses. This will mean an overall decrease in reliability and ease
of servicing. On top of this, fuel consumption of many Euro 4/5
buses is higher than the consumption of Euro 2/3 buses due to the
way emissions-reducing technologies work.
Regards,
Dave
