When it comes to engine fluids, we only use the best stuff. We brought along a few quarts of Royal Purple Max EZ Power Steering Fluid. After the initial fill, we cranked the engine and poured more in gradually as the steering was turned back and forth. This technique ensures that the system gets completely filled. A quality synthetic like Royal Purple will extend the life of our new Series 500 box, while reducing heat-related stress. As we're not running a power steering cooler, we like the extra protection for the occasional track outing.