September 30, 2010

MEMORANDUM				

SUBJECT:	N2O Data from EPA Heavy-Duty Testing 

FROM:	Angela Cullen, Engineer

		Antonio Fernandez, Engineer

Assessment and Standards Division

TO:		Docket EPA-HQ-OAR-2010-0162

This memorandum contains the results of both engine and vehicle FTP
testing.  The vehicle FTP testing values include city cycle and the
highway fuel economy cycle.  The vehicle emission levels reflect the
composite result with the city cycle accounting for 55% and the highway
accounting for 45% of the result.  Vehicle testing was performed at
EPA’s National Vehicles and Fuels Emissions Laboratory (NVFEL).  N2O
measurements on vehicles were made with an INNOVA 1314 Photoacoustic
Multi-gas Monitor and confirmed with a Fourier Transform Infrared
Spectrometer (FTIR). The engine testing was performed at Southwest
Research Institute for the Advanced Collaborative Emissions Study
(ACES), an industry and government collaboration.  In the ACES program,
N2O measurements on engines over the FTP engine test cycle were made
using a FTIR. 

All of the engines tested met the cap of 0.05 g/bhp-hr.  The average of
the engines was .025 g/mi. The engines included 7 tests on 4 diesel
engines from Cummins, Caterpillar, Detroit Diesel and Volvo. 

All of the vehicles tested met the cap of 0.05 g/mile.  The average of
the vehicles was .026 g/mi. The vehicles included 10 gasoline tests and
2 diesel tests.

