The phrase "performance enhancements" refers to improvements or upgrades made to something in order to make it work better or more efficiently. Full definition
The choice of modification depends greatly on the degree of performance enhancement desired, budget, and the characteristics of the engine to be modified. (en.wikipedia.org)
This way of eating is best for performance enhancement, balancing weight, and promotion of overall wellness and vitality. (eatlikethepros.com)
There are also performance enhancements included as part of this update. (zdnet.com)