A Tune Up is performed by using a diagnostic dynomometer (tune scope) to check and adjust the engine and the fuel / ignition systems to ensure peak performance, reliability and fuel economy. A compression / balance test will be performed and results recorded on the invoice. The battery, starting and charging system will be checked together with belts, under bonnet fluid levels and the air and fuel filters. Then a road test will be performed to check for any other possible problems and to ensure all the work performed was satisfactory.