http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4038497/Re:_the_Impact_of_Lubricating_#Post4038497
5W30 to 5W20 with advanced FMs and VIIs lowered engine friction by just over 12%...correlated to 2.3% fuel economy improvement.
5W30 to 5W20 with advanced FMs and VIIs lowered engine friction by just over 12%...correlated to 2.3% fuel economy improvement.