Caterpillar On Track for '07
By Steve Sturgess,
Executive Editor
Caterpillar says it's on target for its 2007 engines launch, according to Director of On Highway Power Systems Greg Gauger during a recent ACERT update and C13 test drive.
With more than 12 million miles of testing scheduled to be complete by mid-October, the '07 engine line-up for on-highway will include the C7, C9, C13 and C15. Missing is the C11, because the C13 will take over ratings previously offered on the 11-liter. The C9 also gets a capacity increase for '07, going from 8.9 liters to 9.3.
ACERT for 2007 builds on Cat's strategy to keep temperatures at the inlet at around 120 degrees, while flowing inert gas into the combustion chamber to minimize flame temperature and hence, NOx formation. Particulates are handled in the exhaust aftertreatment diesel particulate filter.
In an exclusive interview with HDT, Product Development Manager Mike Powers talked about the results of a three-engine teardown comparing two competitive cooled-EGR engines (one example each of a Cummins ISX and a Detroit Diesel Series 60) to a Caterpillar C13. Pointing to high rates of wear in both EGR engines, he said they had shown heavy soot loading at oil changes. All three engines had been run in nearly identical leasing situations. All had done between 350,000 and 380,000 miles on similar coast-to-coast runs, with oil changes at 30-day intervals.
According to the figures presented, soot loadings at oil sampling had typically shown the ISX at 3.55 percent, the Series 60 at 1.94 percent and the Cat at 0.34 percent. Powers said that Cat considers 1.25 percent soot loading excessive.
That, Powers said, led to Caterpillar's decision to go with the clean gas induction version of exhaust gas recirculation, pulling off the exhaust gas at the outlet from the diesel particulate filter after it has been purged of soot. In reality, this means running a small-bore exhaust pipe back up to the engine from the DPF, cooling the exhaust gas further in an on-engine heat exchanger, then inserting the gas into the airstream ahead of the turbocharger(s). The gas then goes with the compressed inlet air through the charge cooler to meet the 120-degree inlet air target.
By pursuing the ACERT technology through this next step, Caterpillar has been able to arrive at a 0.0 percent to 3.5 percent fuel economy improvement, Powers said. And that's testing on the new ultra-low-sulfur diesel fuel, which has a lower Btu thermal content and is expected to lead to less fuel economy. Additionally, because the soot loadings are much lower through using clean exhaust, reliability and particularly durability are not compromised, claims Cat. Powers said that over 500,000 miles, there could be as much as $11,000 to the bottom line.
On The Road
Fuel economy was not to be the subject of this first drive. Rather, the 150 miles up and down the steepest grade we could find in central Illinois were to verify performance and pulling power. But it did give me a chance to see how the ACERT '07 C13 – at its 470-horsepower rating – performed in the real world.
Away from the engine facilities in Mossville, we skirted Peoria and headed from Galesburg, "we" being me at the wheel of the T800 Kenworth daycab with Customer Value Manager Brent Cluskey in the passenger seat. We were loaded to around 80,000 pounds to give the engine as much to haul up the hills as possible, but you'd never have known it. Like all the '07 engines we have driven to date – whoever the OEM – the Cat pulled like a steam locomotive. It didn't matter how low it was lugged (and I went down to 950 rpm on one hill just to see), the turbo boost stayed right with it and the engine was as smooth as silk.
And it was way quiet. I put the sound meter up to my ear in the recognized SAE practice and it registered just 69 decibels. That's quite remarkable, pulling hard at three quarters of rated speed through 45 mph, especially with a daycab. So as well as great performance from the C13, drivers are going to like the peace and quiet.
We headed back and through Peoria to pick up the grades in and out of the river valley. Again, nothing dramatic; it just grunted up the hills. The most we ever shifted was half a gear in the 13-speed.
If there were any regeneration events other than the continuous passive regen in the DPF, I wasn't aware of them. The T8 had the latest dash that included DPF indicator lights, though there appeared to be no switches for the driver to interact in the active regen events. Prior to this drive, I had been out in a Cummins '07 600, which passively regenerated all the time. Subsequently, I drove a couple of Volvo D13s that both went through an active regen. In no case was I conscious of anything going on except for dash lights and, in the case of the Volvo, a deactivation of Eco-Roll (see accompanying story). Again, I saw nothing on the dash except during key-on. So as far as the driver is concerned, DPF regeneration is a non-event.
It was, to be honest, all pretty uneventful stuff. Which, most likely, is what the market wants to hear. There are technologies specific to the '07 ACERT engines such as the DPF, the CGI recirculation and the CRS exhaust heater for active regen. And, shame on me, I don't recall what the CRS acronym stands for. Unless its a reference to my age, as in Can't Remember Stuff.
Drive Test continued...
