Fig. 1. Comparison of GHG emissions (CO₂-equivalent) for different heavy-duty vehicle technologies and fuels: buses were tested using a real-world cycle on a test track, trucks were tested using the chassis dynamometer HD-UDDS cycle.

Fig. 2. Comparison of GHG emissions (CO₂-equivalent) for the 2004 Caterpillar C11 engine operating on different fuel blends with and without the OEM oxidation catalyst.

Fig. 3. Comparison of GHG emissions (CO₂-equivalent) for a 2002 Mack AI-300A engine operating on two fuel blends with and without an aftermarket active regeneration diesel particle filter.

Fig. 4. Comparison of GHG emissions (CO₂-equivalent) for three in-use Class 8 trucks operating on various fuels on the HD-UDDS test cycle.

Fig. 5. Comparison of relative contribution to GHG emissions (CO₂-equivalent) for the 1999 Freightliner operated on LSD over different driving cycles.

Fig. 6. Comparison of GHG emissions (CO₂-equivalent) for 1996 Caterpillar 3126E engine operating on ULSD and B20 Canola.

Fig. 7. Comparison of fuel based CH₄ and N₂O emission factors obtained in this study.

Fig. 8. Comparison of Canadian inventory emission factors and those suggested by this study.

GC-FID parameters for methane analysis

GC-ECD parameters for nitrous oxide analysis

CO₂, CH₄, and N₂O emission rates and fuel consumption (FC) for three different urban bus technologies

CH₄ and N₂O emissions and fuel consumption for two Class 8 trucks with two engine configurations

NM=not measurable.

CO₂, CH₄, and N₂O emissions (g (bhp-h)⁻¹) and fuel consumption (g (bhp-h)⁻¹) for a 2004 caterpillar C11 engine without OEM oxidation catalyst over the FTP HD Transient test cycle

CO₂, CH₄, and N₂O emissions and fuel consumption (g (bhp-h)⁻¹) for a 1995 Mack AI-300A engine with and without an active regeneration DPF over the FTP HD Transient test cycle

NM=not measurable.

CO₂, CH₄, and N₂O emission rates (g km⁻¹, g min⁻¹ for idle) and fuel consumption (L/100 km, L min⁻¹ for idle) average and standard deviation (in parentheses) for three Class 8 trucks operating on LSD, ULSD and various soy biodiesel blends

NM=not measurable.

CO₂, CH₄, and N₂O emissions and fuel consumption (g (bhp-h)⁻¹) for 1996 caterpillar 3126E engine

Heavy-duty vehicle emission factors used in the Canadian national GHG inventory (Environment Canada, 2007) and recommended for US inventory (EPA, 2004)

Fuel based (g L⁻¹ fuel) methane and nitrous oxide emission factors suggested by this study

NM: not measurable.