The use of the chassis dynamometer test cell has been an integral part of the vehicle development and validation process for several decades. Developments in global climate science and environmental health monitoring have driven a wide-ranging debate in the fields of CO2 reduction and air quality improvement. This discourse has focused on road transport and@ especially@ passenger cars because they are a very visible and tangible sector requiring improvement. Events have moved the type approval testing of passenger cars from being a somewhat niche topic understood by a small group of engineers and regulators into a widespread topic of conversation. The deficiencies in historical testing regimes and the failure of some companies to adequately regulate their own work have focused the attention of regulators@ policy makers@ and the public on laboratory procedures and instrumentation methods in an unprecedented manner. For practicing engineers@ it is important to understand our wider role in society@ as well as in our own organizations. In chassis dynamometer testing@ these responsibilities come together and are focused on the delivery of clean efficient vehicles that meet legislative requirements@ as well as customer aspiration. These requirements must be met by vehicles that are robust and durable in the real-world. In addition@ the vehicles must be economically viable in order for the industry to continue providing the affordable mobility which has driven so much economic@ personal@ and social progress over the last century. The pervading environmental lobby presents new challenges to our industry@ and the precise experimental validation of vehicle performance on modern capable chassis dynamometers under realistic operating conditions will be fundamental in overcoming this challenge. The chassis dynamometer test cell design involves specialists in many different fields?? such as mechanics@ ventilation@ and refrigeration??who may not be experts in automotive vehicle engineering. In addition@ automotive engineers may not have in-depth knowledge in all aspects of testing facilities. As the demands on chassis dynamometer testing become more exacting and at the same time more diverse@ the challenge of delivering effective installations and operating procedures becomes ever greater. This book sets out to gather knowledge from both groups of specialists to achieve a better understanding on the testing uncertainties associated with the vehicle chassis dynamometer test cell@ and to enable informed design and the use of these facilities.