Despite being a relatively unsophisticated truck International ProStar driveline smarts on the truck tested by Diesel News are impressive. One of the aspects of this design is relatively new to Australia and this is the ADEPT powertrain technology that can be included in the package when an Ultrashift is specified. This sees drivetrain technology moving to another level.
Much improved data communication sees the driveline delivering quicker, more precise and fuel saving gear changes plus better engine brake performance, when both the transmission and engine work together to maximise retardation.
It was this improved feedback between the engine and transmission that struck this driver in the first few minutes of the test drive. There is a lot more thinking going on behind the scenes so the driver doesn’t have to intervene so often to get good engine braking or feather the accelerator to get an even and fuel efficient acceleration when fully loaded.
The ADEPT (Advanced Dynamic Efficient Powertrain Technology) system, developed jointly by Cummins and Eaton, sees much increased data communication between the engine and transmission, but also further data from the truck’s own system using sensors mounted around the truck.
Out on the highway the Smart Coast ability of the ADEPT system saw the revs drop back to idle when the driveline sensed the momentum and speed of the truck could be maintained safely without the transmission having the clutch engaged. Many times on the test, the truck cruised along at 100km/h with the X15 sitting at 600rpm and the Eaton clutch open. One touch of a pedal or a change in the grade saw the clutch re-engage and the driveline get back on with its job.
Smart Torque uses torque management changes to inform the shifting pattern and keep the engine operating at its most fuel efficient. Knowing whether the truck is unladen or laden changes the response, in terms of torque, evening out acceleration and improving fuel efficiency.
In fact, on this model, the dual-mode Cummins not only adjusts for the mass being carried but also has a sensor on the rear airbag so it knows immediately when the truck unloads and acts accordingly, instantaneously, rather than waiting for the driveline to sense the lower mass.
The Urge-to-Move function is in reverse gear on this model. The system will start engaging the clutch before the driver touches the accelerator. It senses brake pressure is off and starts to move the truck slowly backwards. This is designed to aid slow manoeuvring or coupling trailers. It also makes it a bit like an automatic box to drive. As soon as you release the brake it starts to move, there’s no feathering of pedals. This could be set up to do the same in first gear, but, currently, International only activate it for reverse.
Out on the highway, when it knows it has to work hard, the ADEPT will run the revs out to 1700rpm before going up a gear, but when running on the flat it will have a go at 1500rpm. At top speed, the engine is running at 1500rpm at 100km/h, as it should be on a true Australian US Truck.
The ADEPT system has taken the rudimentary US trucks we know and love and turned them into something which makes the same sorts of noises but also acts in a smart way, mimicking the smarts available from the truck’s European opposition. With Urge to Move, Smart Coast and Smart Torque we are dealing with a dumb truck, with a smart engine and gearbox. US trucks are now in the same electronic ballpark as the Europeans we are seeing on our roads.