Camshaft Types and Their Implications for Vehicle Owners

Most everyday cars, including many older Mercedes-Benz, BMW, Audi, and Toyota models, use a flat tappet cam. The tappets sit against a slightly pointed cam lobe and spin as the cam turns. With good oil flow, they can last a long time. Replacing the camshaft typically requires replacing the tappets as well, as they wear together.

Using zinc-rich oil can help reduce wear in older engines. Newer performance engines, such as those in many modern Porsche, Lexus, and Honda models, often use roller cams. These have a small roller on each tappet that glides over the cam lobe, resulting in less friction, more power, and better fuel economy.

However, roller setups are more expensive and require extra parts to prevent tappet spinning, which can cause serious damage if it occurs. Drivers of European or Japanese vehicles, especially high-performance or hybrid models, may have roller cams in their cars. Issues with the cam or tappets can manifest as ticking sounds, rough idling, or a check engine light.