ENHANCED EVAPORATIVE EMISSIONS VEHICLES

CRC Project Nos. E-77, E-77-2, E-77-2b, E-77-3

Leaders:         C. Hart
                       K. J. Wright

Scope and Objective

CRC, working with EPA, determined a need for an evaporative emissions test program to characterize real-world evaporative emission events for planning and inventory modeling purposes. The goal of this program is to characterize the aging fleet of enhanced evaporative emissions vehicles and to collect data on the newer technology vehicles.  The effects of fuel vapor pressure and ethanol content in the fuel are being evaluated, along with the level of evaporative emissions control technology on the vehicle.

Current Status and Future Program

The pilot program (E-77), focusing on a fleet of 10 vehicles of varying evaporative emissions control technologies and hydrocarbon-only fuels, was completed in early 2007. A Final Report for this work has been released and is available on the CRC Website.

The first main study after the pilot, (E-77-2) is in progress. The vehicles that are being tested include:

• 4 Tier 2/Near Zero LEV
• 4 Enhanced 1996-2001
• One implanted leak (gas cap) vehicle in each category above.

The fuels being tested in E-77-2 are gasolines having the following ethanol content and vapor pressure (VP):

• Ethanol: 0%    VP:   7 psi
• Ethanol: 0%    VP:   9 psi
• Ethanol: 10% VP:   7 psi
• Ethanol: 10% VP: 10 psi
• Ethanol: 20% VP: 10 psi

Testing is ongoing for this project, which is expected to extend into mid-2008.

EPA is funding two follow-on projects to this work, E-77-2b and E-77-3 with  CRC cooperation in technical review and donation of vehicles and fuels.

E-77-2b is a continuation of the E-77-2 test program, with additional cars, using the same test methods. This project is in the contracting phase, and is expected to start in 2008.

E-77-3 is a project targeted at identifying potential fuel leaks in vehicles, and characterizing the emissions of leaks found. The technique selected uses remote sensing devices (RSD) as a screening tool of a high number of passing vehicles, and temporary SHEDs for emissions characterization shortly after identifying a potential leak from the pre-screening phase. A successful pilot study for this project was recently conducted, and the main study will start later this year.

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