Sharing Info, Eaton and Cummins Make an Awesome Powertrain Product

ProStar with 2017 Cummins ISX and heavy-haul Western Star.

As part of an Eaton/Cummins Ride ‘n Drive, I got my first drive of the Advantage setup where the Cummins ISX and Eaton Ultrashift Plus are coupled and ‘talk’ to each other for unprecedented performance and fuel economy. 

This is unique in the industry, with the two participants revealing proprietary information to link their components together for the benefit of the customer. And where each individually might be at a disadvantage compared to emerging integrated powertrains, by this cooperation the two suppliers maintain their opportunities in an increasingly hard-fought marketplace.

Changes for 2017 Cummins are on the inside. 

Eaton sweetened the event with introduction of a new direct-drive version of the Eaton Ultrashift Plus. Cummins brought along additional excitement in a first opportunity to drive the 2017 ISX. The company also announced new ratings available in the Advantage package.

The driving demonstrations were staged at a press ride ‘n drive, held last week at Eaton’s Marshall, MI., proving ground. Cummins brought along two trucks with 2017 versions of the ISX for drivers to experience and compare the new Direct-Drive and the existing Small Step overdrive automated transmissions, and for editors to see for themselves how “driveable” the new engines are going to be.

Eaton’s Direct Drive option joins the Small Step overdrive offering to reach more narrowly targeted customer bases. The overdrive set-up is for line-haul applications where cruise is generally 62 mph or more and engine downspeeding brings economy. 

Low-speed maneuverability enhancements for Ultrashift Plus.

Enabling this are new axle ratios from Dana and Meritor with 2.66- and 2.68-to 1 respectively. The new Advantage Direct is for regional and shorter-haul where urban conditions are more often encountered. In this case speeds are generally in the 50 to 62 mph region.

The rationale is, for highway operations, the inefficiency of an overdrive is more than compensated by the downspeed advantage. In regional operations the fuel efficiency of direct drive is realized. A qualifying matrix allowing customers to see which is better suited to their operations has been released at www.smartadvantagepowertrain.com.

Eaton also debuted two new low-speed operating mode options for the Ultrashift Plus: Urge-to-Launch and Blended Pedal.

The first is easier to understand: Where the normal launch mode is enabled by releasing the park brake, then easing down on the accelerator pedal, the Urge-to-Launch is enabled by simply releasing the park brake. As the brake releases the electronically-controlled clutch closes quite quickly and the truck starts rolling, much as an automatic car would.

A further enhancement is the availability of a creep mode. If the driver stays off the accelerator the truck will stay in the starting gear and roll at idle speed. The driver can then bump gears up with the manual switch to pick up speed, still staying in the creep mode. This is highly useful in a column of traffic that may be rolling at a low speed and saves the truck driver from using accelerator and brake to keep pace.

The second new feature is Blended Pedal and is targeted at vocational customers, especially transit mixer fleets. In this mode the transmission mimics a driver of a standard-shift transmission using clutch slip to slowly maneuver a truck, as in a concrete pouring situation, for instance.

In operation, Blended Pedal uses the first travel of the accelerator as a modulating clutch closer, so the degree of slip is varied from disengagement to full engagement over half of the pedal travel. Then there is a slight dead spot before the accelerator pedal is given back and the truck can be accelerated through the gears as normal. This fine control is enhanced in vocational operations especially by the Hill Start Assist which holds on to the service brakes for up to three seconds in launching on a steep slope.

This was demonstrated in hill starts in forward and in reverse, where the demonstrator mixer could be balanced on the blended accelerator with more pedal travel bringing the truck into motion either backward or forward according to the gear selector position.

Blended pedal is also valuable in highway tractor in reverse when backing under a trailer. Early Ultrashifts with their centrifugal clutch were criticized for a lack of finesse in this situation. With Blended Pedal the driver now has very fine control of backing speed and can control the tractor during coupling to ease slowly into the trailer kinpin.

The opportunity to experience the 2017 ISX and both overdrive and direct Ultrashifts in Inetrnational ProStars showed that the shift regime is different on the differing transmissions. The direct holds on to top gear as long as it possibly can. The overdrive will swap easily between direct top and overdrive to maximize performance.

The 2017 Cummins engines showed great refinement in the accelerator pedal modulation and excellent communication with the transmission(s) enabling smooth shifts both up and down as the transmission controlled the fueling of the engine. The direct Ultrashift also took advantage of the new calibrations for 2017, lugging down to 970 rpms before initiating a downshift.

Feature already available on the Advantage are the two-level Smart Torque and the very effective Smart Coast. The latter disengages the back box in the transmission when the torque sensing sees no load in a mild downhill cruise. The engine drops to idle as the fuel is cut back. The surprising this is how often in general driving Smart Coast is engaged – as much as 30 percent of the time in gently rolling countryside, for instance.

With its 2017s, Cummins will also be simplifying and extending the performance upgrade path for fleets that trade to the second owner. There will be no hardware change when upping engine horsepower at the higher levels, so a fleet that specs 450 hp in its application will be able to uprate the engine to as much as 605 hp for resale, greatly enhancing the trucks residual value.

Eaton’s new low-speed enhancements are selectable through the ServiceRanger service tool. For fleets and owners that don’t have the tool, a dealer can reprogram the shift controller to enable both Urge-to-Launch and Blended Pedal on all transmissions and can be selectable for forward, reverse or both. For more information go to www.Roadranger.com or search on Eaton Ultrashift Plus on YouTube.