The combination of an Irizar Century 3500 body and Mercedes-Benz OH1228L chassis makes for a terrific pairing.
A few years ago Mercedes-Benz introduced the OH 1225 midi bus chassis. Now it has followed it up with the launch of the new Euro 4 version, the OH1228L (0510).
The old 1225 went like a rocket and those who purchased one will love its replacement.
The vehicle ABC took for a run was built for Victorian bus operator Muir’s of Rushworth and is fitted with an Irizar Century 3500 body specced as a school bus.
It is an interesting vehicle in that it has a fantastic looking coach body but when you walk inside there are 45 non-belted McConnell Commuter Mk II seats covered in Holdsworth fabric.
Meeting up at Mercedes-Benz’s Mulgrave facility with Jim Mifsud from Benz and Irizar’s Paul Wheller we took the bus for a run through the back of Rowville and Endeavour Hills to Pakenham then headed for Cockatoo in the Dandenongs for a bit of hill climbing with a photo stop at the Cardinia Dam before returning to Mulgrave.
If anything the ride quality is better and performance is fantastic; the 1228 is quick off the mark and can keep up with the traffic with ease.
There is plenty of grunt and hill climbing was a breeze; with the Irizar body there was no body roll and the bus hugged the road nicely. Gear changes were smooth with no problem finding gears (they just slotted in nicely).
Internal noise was almost non-existent, which made for a pleasant trip.
Internal fittings included luggage racks, curtains, radio/PA/CD sound system, and Irizar’s own Hispacool air-conditioning.
There were three small problems: the first being the driver’s seat was set up for short people and did not go back far enough (later that day I did get a call from Paul saying they’d re-positioned the seat); the second was the location of the hand brake (this rests next to your knee but could be moved back as there is enough room); and the third was where the TV normally sits there is a moulding that hangs down, which if you are a tall person can cause a headache.
Those three little things aside the vehicle was a joy to drive and travel in the McConnell seats was comfortable with leg room being acceptable for an adult and should prove more than sufficient for school children.
Decent-sized under-floor through bins should be ample for the task at hand. The bin floor is the standard ribbed type (not good on the knees) with a top-hinged bin door.
Getting into the bus involves four easy steps of 390mm, 210mm, 210mm and 150mm to the driver’s floor; then two steps of 200mm and 100mm to the flat floor and a final step of 100mm to the rear seat.
The driver’s area is well laid out with all the gauges in easy sight and all the important switches fall easily to hand. There are two control stalks on the column, the left controls wiper/washer, indicators, high beam and horn, the right operates the cruise control.
ZF Servocom 8098 power-assisted steering is light and gives a good feel of the road and makes maneuvering in tight spots a breeze (with a fantastic turning circle), the column is adjustable for reach and tilt.
The brakes on the OH1228L are Knorr SB6000 discs all round with four-channel ABS, EBS and ASR. Incorporating all-wheel wear monitoring and automatic wear adjustment, these are very effective and pull the bus up in no time. The exhaust brake is also effective.
Powering the OH1228L is a Mercedes-Benz OM906LA six-cylinder in-line three-valve turbocharged and intercooled 6.3-litre engine, developing 210kW (285hp) at 2,200rpm and producing 1,100Nm torque between 1,200 and 1,600rpm.
This engine – served by a 200-litre fuel tank and a 25-litre tank for the Ad Blue – is coupled to a Mercedes-Benz G-85-6 six speed synchromesh gearbox with a single-disc dry plate MFZ 430mm diameter clutch with hydro-pneumatic operation.
Gear ratios are: 1st 6.70, 2nd 3.80, 3rd 2.30, 4th 1.48, 5th 1.00, 6th 0.73 and reverse 6.30.
Suspension is full air with an independent front double wishbone and stabilizer bar up front with the rear being an ‘H’ frame with four bellows and shock absorbers.
The axles are a 4,100kg Mercedes Benz VO2 independent unit on the front with a 9,500kg Benz HO4 rigid single ratio hypoid unit on the rear.
Compared with the OH1225L, the new OH1228L seems more refined and a lot smoother.
This combination of the Irizar Century 3500 body and the Mercedes-Benz OH1228L makes for a terrific pairing, be it for school use or as a day charter or tour coach.
Many thanks must go to Jim Mifsud of Mercedes-Benz, Paul Wheller of Irizar and Muir’s for allowing ABC access to this top little vehicle.