Chassis dynamometers are required for different types of regulatory tests like emissions, fuel consumption, etc. as well as for different development tests and running-in of vehicles. With the stringent emission regulations, the chassis dynamometers are required to simulate road resistance accurately and consistently to get repeatable results.This paper describes the new concept of chassis dynamometer using two power devices, an eddy current dynamometer for absorption and a DC machine for generation. Both the machines are controlled through a personal computer (PC) with necessary interfaces. It has been possible to simulate the road resistance accurately on different driving cycles. The software developed has all the required modes for operation. The detailed results are presented in the paper.