Will have to not be used in vehicles which has a moist clutch/friction drives; the outstanding lubricating properties of STP® Oil Treatment for Gearboxes would cut back the friction and cause the clutch to slip. STP® Oil Treatment for Gearboxes is built to lubricate hard to reach places like gearboxes, https://andyykrye.blogoscience.com/40003858/the-fact-about-gearbox-oil-treatment-that-no-one-is-suggesting