In modern era of commercial vehicle industry, comfort is one of the major parameter which improves vehicle running time that will lead to fleet owner's profitability. Air conditioning system is one such system whose primary function is to provide the preferred cooling and stabilize cabin temperature in hot climate conditions. Air-conditioned truck cabin not only gives better driver efficiency, along with comfortable environment for driver improving safety as well. AC compressor consumes power from engine directly affecting fuel economy and vehicle performance. With ever increasing demand for energy efficient systems and thermal comfort in automobiles, AC system needs to be optimized to deliver the required cooling performance with minimum AC power consumption. Hence reducing AC power consumption in vehicle is one of the key challenges for climate control engineers. Variable flow AC compressor is an advanced technology to decrease power input from engine resulting in Fuel efficiency improvement. The objective of this paper is to study the behavior & performance of variable ac compressor for truck application. The compressor was developed and integrated with LCV cabin and further tested. This paper deals in evaluation of various performance parameters that includes cooling performance and FE advantage, which has been tested during Vehicle level testing. The testing is done by simulating duty cycle of real vehicle practice in order to test system with actual field conditions. The test results were analyzed and optimized for further improvement of system.