Should a new turbocharged car use 5w30 or 40?

[MaryRose]

Both 5w30 and 40 are suitable for new turbocharged cars. Turbocharged engines operate under high temperatures and pressures, requiring higher viscosity engine oil to provide adequate lubrication. Effects of low oil viscosity: During normal engine operation, oil forms a protective film on engine components to reduce wear. If the oil viscosity is too low, it cannot form a stable protective film, which accelerates engine wear. Advantages of turbocharged engines: When properly matched and operating under positive boost pressure, they can reduce emissions and exhaust noise while significantly increasing power output with minimal size increase. Disadvantages include slower acceleration response and less linear/smooth operation.