





May 20, 2011


MEMORANDUM

SUBJECT:  	Cummins In-Use Data Collection on SCR Operation

FROM:  	Justin Greuel
		Office of Transportation and Air Quality

TO:  		Docket EPA-HQ-OAR-2010-0444
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      On April 6, 2011, Cummins Inc. provided the following information to the Agency regarding efforts to collect data from SCR-equipped trucks operating in-use.  The information was provided as a supplement to in-use data summarized in comments submitted by Cummins Inc. to Docket EPA-HQ-OAR-2010-0444 on August 20, 2010 (see docket number EPA-HQ-OAR-2010-0444-0011.1).
      
IN-USE DATA COLLECTION RESULTS

   Below is the information Cummins Inc. has collected from 47 different customer owned vehicles (with our 11.9L and 15L engines) operating across the US.  The vehicles have over 2.4 million miles of operation so far.  Cummins has data-loggers on these vehicles' engines.  The data-loggers have an embedded cell phone function, which sends the data to Cummins nightly.  About half the engines in these vehicles are owned by Cummins; the other half are customer owned.  All the vehicles, however, are operated and maintained by the customers.

Of the 47 vehicles:

   * Less than 0.13% of the miles (3,002 miles) were operated where DEF level was in the 5-10% range.

   * Less than 0.03% of the miles (737 miles) were operated where DEF level was in the 2.5-5% range.

   * Less than 0.04% of the miles (918 miles) were operated where DEF level was in the 0-2.5% range (derated performance condition).

   * Less than 0.02% of the miles (516 miles) were operated where DEF level was 0% or empty (derated performance condition).

   * More than 99.7% of the miles were operated where DEF level was maintained above 10% .

   * For DEF quality, less than 0.18% (4,362 miles) of the miles were operated where a faulted condition existed for DEF quality.

