Blue Bird Coachworks 450 LXi, Owner'S Manual

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5-1 Engine Operation
450 LXi Owner Manual
~ 5-1-28 ~ Rev. “C”
5-1.13.4 Cold Mode Operation
Cold mode is initiated if the coolant temperature is below 28°C (82°F). Engine power is decreased until the coolant
temperature reaches the above value. In cold mode, the idle is 800 rpm for the C11 and the C13. The strategy for cold mode
provides reduced smoke emission and faster warm-up time.
After the cold mode is completed, the engine should be operated at low rpm and low load until normal operating temperature
is reached. The engine will reach normal operating temperature faster when the engine is operated at low rpm and low power
demand. This method is faster than trying to reach operating temperature by idling with no load.
Cold mode is disabled if the throttle, the service brake, or the clutch (if equipped) is depressed. The rpm for cold mode
operation drops to the programmed low idle speed in order to allow the transmission to be put into gear.
5-1.13.5 Getting Started
Caterpillar electronic engines do not require long warm-up periods that needlessly waste fuel. Typically, the engine should
be at normal operating temperature in a few minutes. Begin operating the engine at low load. After normal oil pressure is
reached and the temperature gauges begin to rise, the engine may be operated at full load.
To get the vehicle in motion, use a gear that will result in a smooth start. Move the load without increasing the engine rpm
above low idle or without slipping the clutch. Engage the clutch smoothly. Slipping the clutch and engaging the clutch can
cause stress to occur on the drive train. This can also cause fuel to be wasted.
Use progressive shifting techniques. Progressive shifting is using only the rpm that is required in order to upshift into the next
gear. Progressive shifting improves fuel economy.
Keep the engine rpm to a minimum. Use an rpm that is from 1200 to 1600 rpm.
Use only enough rpm to pick up the next gear.
Progressive shifting also reduces the acceleration rate. Top gear is reached sooner because less time is needed to
synchronize the gears during shifting. In addition, the engine is operating at the highest range of torque.
The amount of rpm that is required to upshift increases as the vehicle speed increases, unless upshifts are made on
upgrades. Experience with the vehicle will show the amount of rpm that is required to upshift under various conditions.
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5-1.13.6 Vehicle Effi ciency
An effi cient vehicle performs the desired amount of work while the power demand on the engine is minimized. The following
factors are major contributors to power demand:
Aerodynamic drag (wind resistance)
Rolling resistance of the tires
Gross weight of the vehicle
Losses in the drive train and the load from the engine driven accessories
For more information about vehicle effi ciency, consult the Caterpillar website http:///www.caterpillar.com or consult your
Caterpillar dealer.
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NOTICE: It is not recommended that the vehicle be moved until the engine is out of cold mode. Power may be
noticeably reduced if the vehicle is operated when the engine is in cold mode. At a speed above 8 km/h (5 mph), the
low idle speed will be reduced to the customer programmed low idle speed. The power will still be reduced.
NOTE: These engines may be programmed to encourage progressive shifting. The acceleration rate may slow
down at certain rpm in lower gears. If this occurs, progressive shift parameters may have been programmed into the
ECM. Progressive shift parameters will limit the rpm when the vehicle is driven in higher gears. These parameters are
protected by customer passwords. If the vehicle can be operated in a higher gear at a vehicle speed that is desired,
select the highest gear that is available to pull the load. This recommendation will help to obtain fuel economy. The
engine will be operating at the lowest rpm that is required to pull the load.