Cummins Motor Coach Gearing Recommendations

2015-2016 On-Highway US and Canada (EPA) Products

What matters? Vehicle Mission Electronic Engine Features

and Parameters Gearing Understanding the customer’s

equipment and duty cycle

Application Guidelines Terminology Startability

– The maximum grade (%) on which a vehicle could accelerate from rest during an idle away (closed throttle) start

Peak Torque Gradeability– The maximum grade that a vehicle could ascend while operating

at 100 % throttle in top gear at peak torque rpm

Cruise Gradeability– The maximum grade that a vehicle could ascend at a specified

cruise speed while operating in top gear at 100 % throttle

Guidance for New Equipment Replacement Equipment

– Existing equipment should dictate “Minimum Performance Requirements”

– If tradeoffs are expected, provide customer with adequate explanation and obtain their buy-in

– Driveability (Driver Satisfaction)• Startability• Torque Peak Gradeability• Cruise Gradeability

– Total Cost of Ownership (Owner Satisfaction)• Operational Efficiency and Fuel Economy• Maintenance

Cummins Gearing Recommendations

Gearing Criteria:– Max Fuel Economy:

Aim to maintain the engine operating in a low rpms range, producing adequate power to accomplish the job in an efficient manner, This favors fuel economy over some performance characteristics (i.e. increase in shifting).

– Balance:Aim to operate the engine in a rpm range where horsepower is increasing while peak torque is readily available. This is a good compromise for customers seeking decent fuel economy with solid performance characteristics.

6

Motorcoach Ratings385-500 HP

7

Motorcoach Ratings330-380 HP

8

Motorcoach Rating400 HP

9

Motorcoach Rating320 HP