In 1975 Congress adopted a piece of landmark legislation, the Magnuson-Moss Warranty Act. The Act was designed to prevent manufacturers from drafting grossly unfair consumer warranties and to make it economically viable for consumers to bring warranty suits by providing for the award of attorney’s fees. States built on the themes of the Magnuson-Moss Act by later passing their own lemon laws.
In summary, you can change your oil and perform routing maintenance wherever you want, the factories cannot void your warranty! This is a common misconception concerning automotive repair. For some fun reading Google Moss Magnuson