Can you use the same 5-30wt oil that we on cars for boat motors?

While both cars and boat motors are internal combustion engines, they have different requirements for oil.

5W-30 motor oil is designed for automotive use and is formulated to meet the specific needs of car engines. It may not provide the necessary protection for marine engines in a water environment.

Boat engines are exposed to different environmental conditions, including saltwater, which can corrode engine parts. Marine-specific oils are formulated with additives to protect against corrosion, oxidation, and other harsh marine environments. They also have a higher viscosity to provide better protection for the engine's moving parts.

Using automotive oil in a boat motor can lead to engine damage, reduced performance, and increased wear and tear on engine components. It is recommended to always use marine-specific oils for boat motors to ensure proper lubrication and protection.