Engine oil viscosity debate and owner interval

Tags: #engine-oil · #conflict

Viscosity debate: 20 or 30? One member (KASPER) says 40 is already at the top of the range and recommends 20 for modern turbo engines, with 30 acceptable for naturally aspirated ones. He notes the owner's manual says 10W-30 with API SM, and that oil of such a grade would last only a few thousand km before deposits build up. Another member (Victor) says 30 is fine for calm driving, since aggressive driving raises the oil temperature and lowers its viscosity.¹² Grade and brand experience is collected on the engine oil selection card.

Owner's change interval on synthetic oil. The owner (Oleg Belousov) runs synthetic engine oil and changes it about every 10,000 km in city driving and at 12,000-13,000 km on the highway; he once changed it at 13,000 km after long highway trips. He says he has kept this regime and has had no oil-related problems.³ For much shorter intervals under heavy use see the heavy-duty oil change interval card and the maintenance interval schedule.

Related pages

• Engine oil change — filter, plug, and DIY tools
• Engine oil change interval — heavy-duty usage
• ATF change interval — AISIN guidance, owner debate
• Engine oil — spec, viscosity, and brands
• Engine oil selection — grades and brands

Sources

This page is compiled from 3 community messages. Every fact carries a numbered reference to its original author and message.

Last updated: 2026-10-29