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Power of Choice: New Direct Drive Option for SmartAdvantage™ Powertrain

The ISX15 SmartAdvantage Powertrain is the only integrated powertrain in the industry to offer both small-step overdrive and direct drive options. Understanding the difference between the two technologies and how they match specific duty cycles will help you explain to customers which option will produce the best results for them.

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Small-Step Overdrive

Since its introduction in 2013, the ISX15 SmartAdvantage Powertrain has been mated to an Eaton® 10-speed automated manual transmission with small-step overdrive technology. In its simplest terms, the “step” between 9th and 10th gear (overdrive) is just 26%, which allows the transmission to shift more seamlessly between the top two gears in response to changing terrain and speed operating conditions. Customers with routes across mountainous terrain should always spec the small-step overdrive transmission, regardless of load and number of stops. Long-haul fleets pulling the maximum GVW (80,000 lb) most of the time and travelling 100,000 miles or more per year should also opt for the small-step overdrive transmission, due to the opportunity to leverage direct drive when power on the wheels is needed.

Direct Drive

The direct drive option produces driver-pleasing performance and exceptional fuel economy for fleets that run primarily across flat, rolling or hilly terrain. The 1:1 top gear drive ratio is also ideal for less-than-load (LTL) and regional-haul fleets that carry a lighter average payload, make multiple stops during a single shift and average less than 100,000 miles per year. Three newly approved axle ratios (2.26, 2.28 and 2.39) increase the downspeeding capability, for better fuel economy.

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Every Driver as Efficient as the Best Driver

With manual transmissions, you can see as much as a 30% difference in fuel economy between drivers running the same route. However, with the SmartAdvantage Powertrain’s automated manual transmission, even rookie drivers can run as efficiently as your customers’ best driver, thanks to error-free, guess-proof shifting.

Spec’ing a SmartAdvantage Powertrain is easier than ever with the latest version of PowerSpec.

The fully integrated combination of Cummins ISX15 engine together with an Eaton Fuller Advantage® 10-speed automated transmission is delivering fuel economy that brings 10-14% better fuel economy than that of 2007 and 2010 model-year trucks.

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ADEPT™ is a suite of features that build on SmartAdvantage SmartTorque 2 (ST2), with the adoption of SmartCoast,™ and interaction with predictive cruise control (PCC), which adjusts torque level and speed based on look-ahead terrain data and GPS information.

To learn more about the engine and transmission technologies keeping the SmartAdvantage Powertrain a step ahead of the competition, visit

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