in just a few months i have been lingering in this website, i have seen a lot of discussions of engine top and major overhauls. today's cars and engines are designed way above the cars that needed frequent visits to the crusty "mechanic" for tune up around 20000 miles, valve adjustment every six months, decarbonize combustion chambers every now and then and the list goes on. sure these "mechanics" need to earn a living, but your engine's metallurgy, design, engineering and expected endurance has far improved. there is absolutely no need to overhaul your engine for at least 15 years if you follow the maintenance schedule, use the recommended fluids and refrain from tampering the car specially if you don't have the knowledge, skills and the tools necessary to do tasks above oil changes, spark plug replacement or air filter replacement. that's why some car manufacturers use tamper resistant fasteners in fact, some cvt equipped cars do not provide you a dipstick nor a provision to add the wrong fluid.