Auto Stop/Start

There is much debate on this topic. After watching many videos, this topic is quite complex since there are many things to consider.

Considerations

Auto Start/Stop

Auto Start/Stop systems repeatedly shut the engine off and restart it at stoplights, increasing the number of start-up cycles far beyond what older engines experienced. These extra cycles place added stress on bearings, the starter system, timing components, and lubrication because most engine wear occurs during start-up before full oil pressure builds.

Low Tolerance in Modern Engines

Modern engines are built with extremely tight tolerances, meaning components have very little space between them and rely on a stable oil film to prevent metal-to-metal contact. While this improves efficiency and power, it also makes engines more sensitive to oil quality, viscosity stability, and lubrication delays during start-up.

Low Viscosity Oils

Manufacturers specify low-viscosity oils like 0W-20 to reduce friction losses and improve fuel economy, but these thinner oils provide a smaller protective film thickness. In high-stress conditions or frequent start-stop situations, the reduced film can make engines more vulnerable to wear if the oil thins out further.

Viscosity Breakdown

All engine oils thin as they heat and shear, but modern thin oils are more prone to losing viscosity over time, reducing their ability to maintain adequate separation between moving parts. When viscosity breaks down, especially in engines with tight tolerances, bearings and cam surfaces can experience accelerated wear.

References

Hybrid Uniqueness

Auto S/S Implementation