Prestone® Power Steering Fluid + Stop Leak (PSF+SL) delivers increased system life and prevents & stops system leaks. Stop Leak additives renew, restore and condition seals in the power steering system. These seals harden and shrink over time which are the likely cause of leaks. The stop leak additives also prevent leaks by rejuvenating seals before they leak. Also designed with Anti-wear System Protection, Prestone PSF+SL protects against pump failure, squeals and clogs. This 50,000 mile fluid life is formulated for use in all manufacturers; cars, SUVs, crossovers, and light and medium duty trucks. This a conventional fluid. Many cars 2006 and newer use synthetic based fluids for longer life and better protection. Conventional and synthetic fluids can be mixed but performance and replacement intervals are reduced by the conventional fluid.