What maintenance do mild hybrids require?

The maintenance of mild hybrid electric vehicles (MHEV) requires coordinated care for both the traditional fuel system and the 48V electrical system, with the core focusing on three aspects: oil compatibility, battery management, and system inspection. Since the engine of an MHEV remains the dominant power source, low-viscosity fully synthetic oil of 0W-20 or 5W-30 should be selected to accommodate frequent start-stop conditions. For example, the minor maintenance cost for a Toyota Corolla Cross Hybrid is approximately 500-600 Malaysian Ringgit. Although the 48V lithium battery pack does not require active charging, its state of health needs to be monitored regularly to avoid prolonged undercharging (It is best to maintain the charge level between 20% and 80%). The battery cooling filter should be cleaned and the wiring harness insulation inspected every 20,000 kilometres. Medium-intensity mechanical braking should be performed 3-5 times monthly to maintain brake disc effectiveness, and brake pad replacement intervals can be extended by 30%-50% compared to conventional fuel vehicles. Special attention should be paid to the belt-driven integrated starter-generator (BSG) in MHEVs, which requires belt tension inspection every 40,000 kilometres, while transmission fluid replacement intervals may be extended to 80,000-100,000 kilometres, provided manufacturer-specified fluid is used. Overall, MHEVs have 15%-20% lower annual maintenance costs than conventional vehicles, but strict adherence to the manufacturer's hybrid system inspection requirements is essential.