The Power of Volvo: 2017 powertrain enhancements
Behind the scenes with the engineers who developed Volvo’s new 2017 powertrain and the real-life customer testing of the transmission and engine improvements resulting in the most fuel efficient lineup yet.
While many companies saw the changing rules to be a negative, Volvo viewed the looming 2017 GHG emissions regulations as an opportunity to expand its powertrain and engine capabilities while maintaining durability, maximizing uptime, and improving fuel efficiency. The new Volvo 2017 powertrain lineup includes a wide range of productivity-enhancing transmission and engine improvements made possible by the engineers and product managers behind the scenes as well as the real-life customer testing of the cutting-edge technology.
Take a first look at detailed insight into the new powertrain lineup, how it works along with analysis from Watkins and Shepard Trucking drivers who field-tested the new technology including the Variable Geometry Turbocharger (VGT) Turbo Compounding (TC) engine and Volvo I-Shift.
START YOUR ENGINES
The story begins with Volvo’s D11 and D13 engines, designed for long-haul, regional and local distribution applications. Volvo relied on the solid foundation of its mature, proven medium-block architecture, and married it with numerous innovative technologies to meet its 2017 goals.
Bill Meacock, project manager for the D13 TC engine, says Volvo’s quest to improve their powertrains exceeded the need to meet 2017 regulations. The ambitious agenda included improving reliability, improving fuel efficiency, reducing engine weight, improving performance, maintaining durability and, of course, reducing emissions.
“Being part of a worldwide organization made rapid advancements possible,” says Jason Evans, project manager for the D11/D13 VGT engine.
“We can build on our base product with technology that has been proven globally in other markets and apply that to the U.S. market,” he says. “We also benefit from the additional validation testing experience prior to introducing the technology to the U.S, market.”
At a time when emissions compliance strategies can place undue focus on cutting displacement or performance, Volvo chose to pursue a path of first getting as much as possible out of every drop of fuel consumed. Fuel that leaves the engine unburned does nothing to help fuel efficiency or performance and has a negative impact on exhaust emissions. All else being equal, any improvements in combustion serve to address three of Volvo’s key powertrain goals: fuel efficiency, performance and emissions.
A new common-rail fuel system and introduction of a low-friction wave piston design are the key elements of this improved combustion package. The common-rail fuel system’s finer control allows quicker, more accurate fuel injection for improved fuel efficiency, while the new wave design on the face of the piston increases cylinder efficiency by optimizing flame propagation toward the center of the cylinder.
The improved combustion package is just one example of how Volvo’s North American products benefit from the company’s global footprint. “The new common-rail fuel system, injectors and pistons, have been in production in other markets throughout the world since late 2013,” Meacock says. “So there has been a lot of development testing beforehand that we were able to pick up on and didn’t have to repeat.”
Elsewhere on the engine, an improved intake throttle speeds engine warm-up, allows better control of aftertreatment temperatures, and smoothes engine shut-down. There’s also a new two-speed coolant pump that reduces parasitic losses to improve fuel efficiency.
“The quest to improve Volvo’s powertrains exceeded the need to meet 2017 regulations.” - BILL MEACOCK, PROJECT MANAGER FOR D13 TC
LESS WASTED HEAT
For long-haul applications with extended periods of steady-state engine speeds, the Volvo D13 TC uses turbo compounding to recover energy normally lost through exhaust heat. Turbo compounding employs a second exhaust turbine, downstream of the turbocharger, which routes the recovered energy through a shaft to the engine flywheel.
“Turbo compounding lends itself very well to downspeeding, which in turn lends itself to fuel efficiency,” Meacock says. “You can apply turbo compounding in two different ways. One is to just simply increase the overall output of the engine. Our approach is the other direction: we want to maintain and improve the low-end performance, allowing us to gain a balance between good drivability and downspeeding.”
As with the combustion improvements, turbo compounding is another example of prioritizing the reduction of wasted energy over cutting performance or displacement.
A key to reducing emissions, Volvo’s “one-box” exhaust aftertreatment system provides better thermal encasing of exhaust energy, improving muffler efficiency, while the use of CuZ (copper zeolite) catalyst coatings improves both low-temperature NOx conversion, and long-term system robustness. The one-box system also reduces weight and offers smaller system packaging to free up precious frame-rail real estate under the cab.
“We can build on our base product with technology that has been proven globally in other markets and apply that to the U.S. market.” - JASON EVANS, PROJECT MANAGER FOR THE D11/D13 VGT ENGINE
FASTER SHIFTING WITH I-SHIFT
When it comes to powertrain news, new engine features frequently overshadow transmission technology, but for 2017, Volvo’s I-Shift automated manual transmission also benefited from numerous upgrades. Volvo saw the I-Shift as an equal priority for upgrades as its popularity has supported momentum for Volvo engine sales.
Internally, there are upgrades to improve durability, reliability and performance. “To minimize component wear and improve shift synchronization, it’s necessary to control the speed of the transmission’s main shaft and countershaft during shifts,” Cesar Moreira, project manager for I-Shift, says. “To accomplish this, Volvo uses a system of friction discs in the front of the transmission called a countershaft brake. This component wears with time, so we used a new design with more friction discs, improving reliability compared to the current design.”
The I-Shift technology also benefits from updates to its control computer and shift algorithms, enabling faster and more precise shifting under challenging conditions.
LOW SPEED CONTROL PLUS HIGH SPEED EFFICIENCY WITH I-SHIFT WITH CRAWLER GEARS
Another major transmission update for 2017 is the I-Shift with Crawler Gears option, which adds either one or two, depending on selected spec, to the base I-Shift: low gear and ultra-low gear.
When steep-grade startability and low-speed maneuverability are critical, the I-Shift with Crawler Gears offers the highest weight capacity in an automated manual transmission. It enables controlled forward and reverse travel at extremely slow speeds. Upgraded software optimizes shifting for high GCW applications, allowing shifting to occur at higher revs, and enabling drivers to control downshifts.
“The Crawler Gears allow the transmission to be more flexible, with a wider overall gear ratio. This offers the benefit of good low-speed control while being able to maintain low RPM at cruise speeds,” Moreira says. “This is especially an advantage at high GCW loads where a faster first gear would otherwise require a lower axle ratio. The Crawler Gears option enables keeping the more fuel-efficient, higher axle ratio, while preserving startability on steep grades.”
PREDICTIVE PERFORMANCE WITH I-SEE
Combine I-Shift with an intelligent cruise control and you get I-See, a unique system that learns the topography of the road. Later on, it automatically uses its knowledge to save fuel when the intelligent cruise control is engaged.
I-See works with Volvo engines and I-Shift transmissions to manage road speed and gear shifting in the most fuel-efficient way. Instead of relying on GPS and cellular coverage that can be compromised in mountainous terrain, I-See memorizes the actual grades along your route, taking advantage of kinetic energy to lower fuel consumption when activated.
“I-See uses the truck’s powertrain data to learn the road topography, and to predict what is the best strategy for the next hill. All the time it is learning, and all the time it is improving. It’s a continual learning process,” Moreira says. “I-See does not rely on external mapping data. Anywhere on the planet, the system keeps working.”
REAL WORLD TESTING
As much as internal testing and validation in other markets have contributed to the fine-tuning of Volvo’s 2017 powertrain components, the ultimate proof lies in how the new technology performs in the hands of real-world customers, subject to the unique demands of the North American market. To accomplish this final stage of testing, Volvo relies on an extensive fleet of test vehicles placed in a diverse array of North American customer fleets.
“We really tried to test from an end-user’s perspective, across as much of the range of usage for these truck as possible,” says Glenn Hindeliter, group manager for field test customers. “Within our field test program, we have 26 customers operating nearly 50 trucks throughout North America. They are testing equipment in rugged terrains, ranging from the cool mountain ranges of Canada, to the hot and humid weather of Florida, to the hot and dry climate of Texas. It’s really important to the project team to rack up not only all the miles they need for reliability growth calculations, but also to include a wide range of applications as well.” The variety of customer fleet applications represented in the testing program was specifically chosen to inspire a high degree of confidence that the new powertrain components would perform reliably in virtually every application.
Ultimately, what matters most in the testing process is how the truck and its powertrain perform in a real-world customer application. Among the customers in Volvo’s fleet testing program is Helena, Montana-based Watkins & Shepard Trucking, a nationwide dry freight carrier.
“The Crawler Gears allow the transmission to be more flexible, with a wider overall gear ratio. This offers the benefit of good low-speed control while being able to maintain low RPM at cruise speeds.” - CESAR MOREIRA, PROJECT MANAGER FOR I-SHIFT
Mike Halpin, a 26-year veteran driver for the company, along with his wife and co-driver, Wendy, make up one of two teams at Watkins & Shepard testing the new Volvo powertrains. The two teams run roughly identical routes, with Halpin’s truck powered by the base-model D13 VGT, and the other team running the D13 TC.
Running between 300,000 to 400,000 miles per year, a typical route begins at the Montana terminal, then heads to California, New Jersey, Georgia, and back to Montana. Most loads are at or near max GCW, in a drop-and-hook, terminal-to-terminal operation. The route and distances involved enable Volvo to quickly collect operating data in a wide range of operating conditions.
Operating data from the truck is collected electronically, often in real-time. If Volvo needs to get hands-on with the truck, they work through a dedicated technician at the Montana dealership, or, if needed, the proximity of Halpin’s route makes it easy to stop in at Volvo headquarters in Greensboro, North Carolina.
The low engine noise level is among the most notable of Halpin’s observations to date. “It’s the quietest engine we have had for a long time,” Halpin says. “When you have it at a truck stop idling, you have to go look for it, because you can’t hear it.”
Operating on icy mountain roads in the Northwest during the winter, Halpin has had ample opportunity to experience the close integration between the I-Shift transmission and D13 engine. “We run super singles (wide-base tires), and when we downshift, the amount of torque delivered to the tires in the lower gear is the same as it was in the higher gear. There’s no slipping,” Halpin says. “All these years, I’ve never had to put chains on.”
Halpin’s truck has more than 200,000 miles on the 2017 powertrain, accumulated over a period of nearly eight months, with no service or downtime issues. “It’s almost like being in a jet airplane,” Halpin says. “It’s not gonna break.”
THE BOTTOM LINE
So what does all this new hardware, technology and testing ultimately mean for the customer’s bottom line?
Fuel efficiency is the main bottom-line benefit. “The benefit the customer is going to see is improved fuel efficiency, ranging from 2.5 percent on the D13, to up to 6.5 percent on the D13 TC,” Evans says. “The fuel and weight savings results in a more profitable operation for customers.”
“It’s an evolution, not a revolution,” Meacock says. “An evolution of an already great product that’s maximizing fuel efficiency without sacrificing drivability or durability.”
Maintaining durability and maximizing uptime are Volvo’s top priorities for the 2017 powertrain updates. “As part of our reliability growth program, we are measuring and predicting fault frequency after six months in service,” Evans says. “Our target is a fault frequency that is lower than our current products, and that will all lead to more uptime for the customer.”