ACUITY Shifter Spring. This spring was designed to improve the centering action of your 10th Gen's stock shifter. If you've ever found the centering action of your shifter to leave you wanting a sportier feel, the solution is finally here. With a notably increased preload and nearly identical rate, the ACUITY Performance Shifter Centering Spring increases the centering load in neutral without significantly increasing the force required to locate the far gates (e.g. 1/2 and R). The end result is a sportier shifting feel without an increase in driver fatigue or a reduction in drivability. This spring is designed to provide a 100% increase in spring force on the Sport model and a 20% increase in spring force on the Si and CTR. This translates to about a 50% increase in centering force at the knob in the Sport model and about a 10% increase at the knob in the Si and CTR. In addition to the Performance Shifter Centering Spring, each kit is supplied with a small packet of premium silicone grease to re-lubricate the shifter with after removing the OEM spring.