Does Bell Hammer Light last about 4 months, with its coating fading gradually if not re-added? Does LS Bell Hammer last around 4 years/40,000 km without shortening the cycle, and is Gold more durable under heavy use?

Engine oil (Bell Hammer Light)
When added to engine oil, Bell Hammer Light forms a lubricating film on metal surfaces to reduce wear and maintain smooth operation. For a 4-month oil cycle, it remains effective throughout the period.
Even if not added at the next oil change, the coating does not vanish immediately; it gradually fades with mileage. To keep consistent performance, re-adding 5–10% at each oil change is recommended.

MT gear oil (LS Bell Hammer concentrate)
MT gear oil has a long standard replacement interval (about 4 years or 40,000 km), and this does not need to be shortened when LS Bell Hammer concentrate is added. Because gear sections are less contaminated, the film lasts long.
However, for frequent high-load or circuit use, LS Bell Hammer Gold—with higher heat and wear resistance—is the better option.

Summary
・Engine oil: Re-add every 4 months for stable effect; the film remains for a while even if skipped once.
・MT gear oil: No need to shorten the cycle in normal use; use LS Bell Hammer Gold for heavy-duty conditions.