1.1 ,This test method covers a vehicle test procedure for evaluation of intake valve deposit formation of unleaded spark-ignition engine fuels. This test method uses a 1985 model BMW 318i2 vehicle. Mileage is accumulated following a specified driving schedule on either public road or test track. This test method is adapted from the original BMW of North America/Southwest Research Institute Intake Valve Deposit test and maintains as much commonality as possible with the original test. Chassis dynamometers shall not be used for this test procedure as the BMW NA/SwRI IVD Test was not intended to be applicable to chassis dynamometers and no correlation between road operation and chassis dynamometers has been established.