Embodiments of branched polymer lubricant additives comprise a branched polymer and, when combined with a lubricant base at a concentration from 1 wt % to 50 wt %, provide (i) a viscosity index .gtoreq.150, (ii) that is at least 10% less than a coefficient of friction of the lubricant base alone in contact with a component of a device during operation of the device at a temperature within a range of 20 to 100.degree. C., or (iii) both (i) and (ii).
ACKNOWLEDGMENT OF GOVERNMENT SUPPORT
 This invention was made with government support under DE-AC0576RLO1830 awarded by the U.S. Department of Energy. The government has certain rights in the invention.