I-Torque™ can make 8.5 MPG possible even at top road speeds

The challenge has always been deceptively simple. Make great fuel efficiency possible for nearly everyone, without sacrificing performance. For years no manufacturer could really crack that nut, until I-Torque™.” Duane Tegels is Volvo Trucks NA product marketing manager for vocational and powertrain and he’s understandably proud about what the company has achieved in the new I-Torque system. “It’s been the holy grail for a while. Push fuel efficiency up over 8 miles per gallon, for a wide variety of applications, while still making a truck that’s powerful. We think I-Torque is going to ultimately change perceptions of what kind of fuel mileage is acceptable in a Class 8.”

I-Torque is a complete powertrain package. It starts with the D13 Turbo Compound engine, which is paired with the 13-speed Volvo I-Shift transmission. The engine and transmission are then paired with fuel-efficiency software and map-based I-See predictive cruise control. Together these allow for proactive shifting as the entire truck works to provide power and fuel savings.

Map-based I-See is a vital component of the I-Torque system. It helps the truck to
anticipate the topography and decide the most fuel-efficient points to begin
coasting or to downshift for the next climb.

“We’ve created one powertrain specification that is extremely flexible, independent of load, independent of road speed requirements,” says Johan Agebrand, Volvo Trucks director of product marketing.

"We’ve created one powertrain specification that is extremely flexible, independent of load, independent of road speed requirements."
Johan Agebrand, Volvo Trucks Director of Product Marketing

We’ve seen in our simulations and real-world testing that we can achieve eight and a half miles plus per gallon. This has been possible with all kinds of loads and terrain. It’s a really wide sweet spot for fuel efficiency that starts at 55 MPH. Then it just goes up and up.”

Uniquely North American

The combination of higher speed limits and much longer routes makes the U.S. a transportation market unlike any other in the world. Other large truck markets like Europe and Asia simply don’t place the same distance and speed demands on a powertrain.

“Very few global powertrain manufacturers have been willing to design a fuel-efficiency solution that would only work in North America,” according to Magnus Koeck, Volvo Trucks vice president for strategy, marketing, and brand management. “Our product designers have developed a very fast, very efficient option that specifically meets the needs of the drivers here. We are extremely proud of that.”

Easy to start, easy to drive

One of the secrets to I-Torque’s improved fuel efficiency is a rear-axle-ratio as low as 2.15. With ratios as fast as these, startability and time in top gear naturally become a concern. So, Volvo pairs the 13-speed I-Shift transmission with this powertrain. With a first-gear ratio of 17.5:1, stability is no longer a concern and time in top gear becomes a thing of the past.

The D13TC’s unique torque curve and faster rear axle ratios allow the drivetrain to use the top two gears in their most efficient applications. Top gear is used when lightly loaded or on flat terrain (ex. 72 mph @ 1037 rpm), while direct drive delivers greater power and efficiency when pulling steeper grades or loads (ex. 72 mph @ 1321 rpm/455 hp). The 13-speed I-Shift’s deep reduction reverse gears also create a unique side effect, allowing for a safer and slower reverse speed when backing into tight areas.

" The engine produces a lot of torque down low, so we’re able to move loads at faster speeds while maintaining low rpms and be extremely fuel efficient."
Duane Tegels, Volvo Trucks Product Marketing

“The engine produces a lot of torque down low, so we’re able to move loads at faster speeds while maintaining low rpms and be extremely fuel efficient,” says Tegels. “It’s the adaptability along with the efficiency that is really the game changer here. We don’t do just one thing well. We want to do everything that the driver may encounter. They may run in the mountains, they may be on the flat, or they may be on a two lane that has a lower speed limit. This truck is fully capable of adapting, operating at lower rpms with more power.”

Reduced noise in the cab is a welcome added benefit of I-Torque. Lower rpms from the D13TC creates a quieter overall driving experience and potentially decreases distraction and fatigue.

Bottom line impact

I-Torque offers bottom line savings for fleets. By offering up to 8.5 miles per gallon, even at top road speeds, the system can deliver a 31% increase in vehicle speed range. It also provides more horsepower at lower rpms than any other engine, including larger 15-liter options. So, there is no compromise on performance to achieve fuel efficiency.

“Not only are transportation companies going to see the savings while they are running the truck, but we also believe that I-Torque is going to be a boon for resale value as well,” shares Agebrand. “For instance, a fleet doesn’t have to spec a truck just for running in the mountains. Choosing I-Torque is going to mean your powertrain is flexible enough to meet your current needs, as well as the future needs of almost any secondary owner around the country. We think these I-Torque equipped trucks are likely to get a premium when the time comes for resale and that only improves their lifetime cost-of-ownership.”

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