Adapting a Geo Metro to Run on Natural Gas Using Fuel-Injection Technology

This project involved adapting a Geo Metro to run on natural gas using fuel-injection technology. The stock electronic control unit and catalytic converter were used. The subcompact vehicle was equipped with a light-weight storage tank, a single-stage regulator, and a natural gas fuel injector which replaced the gasoline injector in the throttle body.

The vehicle was tested for emissions using the U.S. Federal Test Procedure. The results indicate that we are close to meeting our objectives of developing a low-cost, environmentally friendly vehicle that runs on natural gas and that has a good driving range. The combined-cycle driving range was 498 km (309 mi). Tailpipe emissions at 10,000 km (6,200 mi) are presented for carbon monoxide, oxides of nitrogen, and non-methane hydrocarbons. In addition, data are presented on non-methane organic gas emissions based on hydrocarbon speciation tests, maximum incremental reactivities, and reactivity adjustment factors.