To keep temperatures stable, a custom aluminum intercooler is paired with a high-capacity coolant reservoir, while a 107% larger radiator doubles the cooling capacity of previous Roush low-temp radiators. A Roush-developed billet aluminum viscous crankshaft damper helps keep the engine reliable, as do specially developed spark plugs that prevent knock and detonation. Although the kit is optimized for 93-octane gas, 91-octane fuel will also work without impeding all factory driving modes.
Roush says that all of these components have been tested thoroughly, enduring more than 900 hours of engine dyno time, as well as development drives in hot weather and cold chamber validation to confirm that the cold-start procedure is unaffected.