A bonus at the Eaton-Cummins event held last week in Detroit event was the pleasant discovery that all the International ProStar tractors available for test drives — we were testing the automated manual transmission/powertrain upgrades — were fitted with 2017-compliant Cummins ISX15 diesel engines.
It was the first time trucking industry journalists were allowed to evaluate the new engines, which Cummins on-highway marketing manager Mario Sanchez-Lara called “game-changers” for the trucking industry.
Details were obviously few. We weren’t even allowed to peek under the hoods. But my test drives in loaded ProStar tractors showed the engines to be peppy in terms of acceleration, quiet and instantly responsive to throttle inputs. Instantaneous fuel economy numbers logged by the driver information center were impressive as well: 9.7 mpg seemed to be my average result when in cruise control, although I did note numbers as high as 12.7 mpg on very slight downhill grades.
As expected, fuel economy numbers went through the roof when the SmartAdvantage’s SmartCoast function kicked the drivetrain out of gear on downhill grades. This system puts the powertrain in neutral with a corresponding deep reduction in engine RPMs to obtain maximum fuel economy. When the transmission senses the end of the downgrade it seamlessly reengages the drivetrain as naturally as any seasoned driver would.
We’ll have to wait a bit longer to get concrete details on the Cummins’ 2017 engines, but the company is decidedly upbeat about their early beta-test units, which are undergoing real-world testing now.
Sanchez-Lara told me when this evaluation phase is complete, Cummins will have logged over 9 million test miles on the engines in real-world fleet applications. Around 20 of the engines will have logged around 250,000 miles apiece when testing concludes. Several other units will have approximately 500,000 miles on them.
So far, Sanchez-Lara says the test fleets are impressed, reporting significant improvements in fuel economy, serviceability and maintenance intervals. In some cases, he says the improvements over current diesel engines will be “eye popping.”
– by Jack Roberts