The rapid increase of passenger vehicles in the automobile sector all over the world lead to continuous increment of the vehicle exhaust pollutants and fuel consumption rate. Despite numerous enhancements in advanced vehicle engine technology, these issues are still of great importance to worldwide researchers. This paper details the development of instantaneous emission models for computing the exhaust pollutants such as hydrocarbon, nitrogen oxides and carbon oxides from passenger vehicles on urban plain road conditions. In this experimental work, Maruti Swift and Alto gasoline vehicles are selected for evaluating the fuel consumption and instantaneous pollutants at various vehicle speeds and acceleration conditions. The results reveal that the best fuel economy speed of Swift and Alto vehicle is 50 kmph and 55 kmph respectively. It is also seen that the results from developed empirical models are in good agreement with the experimental results data.