Heavy Duty Trucking, March 2020

Integrating the powertrain with various proximity sensors allows the computer to intervene with braking deceleration and possibly steering to minimize the potential for collisions uphill grade is a delicate one Drop too low in the torque band and it feels like someone turned off the key But letting the engine pull down to 1000 or even 900 is fine if the engine knows that relief is just ahead Good drivers would watch the road ahead and predict if a shift was needed predictive cruise does that now adding GPS eyes to the powertrain that enable it to hold a gear as long as possible or to know when to give up and downshift earlier Options like Volvos Dynamic Torque can manage torque under different load conditions When lightly loaded below 65000 pounds torque is reduced on acceleration to reduce fuel consumption and driveline wear when extra power isnt needed such as when bobtailing or empty For heavier haul applications programming allows the transmission to lock out overdrive and keep it in direct This enhances performance when heavy with a minimal fuel penalty In effect a single engine can be programmed to perform at its best under quite different load conditions Customers can tailor the drive mode software to match their fuel economy or performance requirements says Moore Most engine makers offer dual torque configurations too The lower torque setting is active in the lower gears where high torque output isnt needed and can be damaging to driveline components but available in the higher gears This eliminates ownership and consultancy leader Adept can provide electronic decisions to the powertrain that can at times make better decisions regarding efficiency than the operator can Better torque management Perhaps one of the most beneficial examples of smart powertrain thinking is downspeeding running at very low engine rpm at cruise speed to reduce fuel consumption It would not have worked back in the days of mechanical engines and manual transmissions even though some variation on the gear fast run slow concept was popular Drivers would have been intensely unhappy with the feel of the engine at very low rpm so they would have likely run a gear or two back or cruised at 80 mph or more as the gear sets allowed Either way the fuel savings would have been negated When cruising at 1100 rpm the question of whether or not to downshift on an momentum with the parasitic engine drag Features such as predictive cruise control use GPS and terrain maps to read the road ahead and plan acceleration gear shifts and engine brake applications to keep the truck rolling as efficiently as possible without unnecessarily extending trip times On an uphill grade for example the GPS will tell the engine its approaching a 1 mile long 3 grade Based on the weight of the truck the engine may calculate it can climb that hill without a downshift But on a 15 mile hill if the engine determines it might need a downshift midway up it may instead make the downshift before it hits the hill to avoid shifting on the hill and losing momentum in the process The various algorithms built into the ECMs favor fuel efficiency in many cases but they can be programmed to lean toward performance if thats what the operator wants In the old days a fleet might give a driver a high powered truck and hope they would use the power responsibly While a driver can still override some of todays programmed shifting and acceleration parameters they usually dont Its not worth the effort Its simply easier to let the computers do the thinking When I think of smart powertrains like Cummins Adept we have provided customers the ability to customize their powertrain for its particular use says RaNae Isaak Cummins powertrain total cost of Using preloaded terrain maps IPM will adjust the following distance to ensure the truck is carrying the most efficient momentum into road conditions ahead Kelly Gedert Daimler Trucks North America MARCH 2020 HDT 49 WWW TRUCKINGINFO COM