Abstract
A road vehicle is continuously subjected to varying operating conditions and it is very seldom that steady state running occurs over a period of any length. The main operating parameters are vehicle speed, load and acceleration or deceleration, with associated gear changes. Even on a highway, where a steady speed can be maintained, the load factor of the prime mover will vary according to the road gradient.
In this paper, we describe the conversion of a spark ignition engine of passenger car Fiat 125P, so as to work on either gasoline or compressed natural gas by the same ignition circuit. A flexible rubber bag is constructed and prepared to store the exhaust gases during running on a road surface. In order to evaluate the importance of using compressed natural gas as a fuel in the passenger car, tests have been carried out on a level road surface. A comparison of the experimental results for both gasoline and compressed natural gas (CNG) shows improvement in exhaust emissions. Results indicate that vehicles fuelled by compressed natural gas have lower level noise, vibration and emissions of carbon monoxide and hydrocarbon than gasoline fuel.