01/04/2026
TOTW:
Engine oil viscosity; 0W20 or 5W30?
In the last few years, several major vehicle manufacturers have issued recalls and endured lawsuits over catastrophic engine failures. Such as:
Toyota: The company has faced major recalls for its 3.4-litre twin-turbo V6 (V35A) engines used in certain Toyota Tundra, Lexus LX, and Lexus GX models from 2022–2024. The issue stems from manufacturing debris left inside the crankcase, which can damage crankshaft bearings and cause the engine to seize unexpectedly.
General Motors: Nearly one million GM trucks and SUVs equipped with the 6.2L V8 L87 engine have been subject to recalls and investigations for potential catastrophic failures due to defective connecting rods and/or crankshaft components. Affected vehicles include models like the Cadillac Escalade, Chevrolet Silverado 1500, and GMC Sierra 1500 from the 2021–2024 model years.
Hyundai/Kia: A decades-long issue involving their Theta II, Gamma, and Nu engines has led to massive recalls (over 3.3 million engines investigated or recalled). Failures are linked to metallic debris from the manufacturing process that can cause engine knocking, stalling, and fires.
Honda: Around 250,000 vehicles with 3.5L V6 (J35) engines from model year 2023 were recalled due to improperly machined crankshafts leading to bearing wear and connecting rod seizure. An expanded federal investigation now covers over 1.4 million vehicles with V6 engines due to numerous failure complaints.
Nissan: In 2025, Nissan recalled nearly 444,000 vehicles, primarily 2021-2024 Rogue models with 3-cylinder engines, for potential engine failures caused by manufacturing defects and metal debris.
Of note is how manufacturers blame "debris" or "manufacturing defects" as the cause of the failures. I cannot dispute their reasons, however they all have another common denominator that is causing a lot of debate.
THEY ALL SPEC 0W20 ENGINE OIL (as determined by researching owner's manual information from each manufacturer).
This post would be way too long if I attempted to try and explain how engine oils perform inside your engine. And needless to say there are millions of engines running just fine on low viscosity (0W20) oil for hundreds of thousands of kms.
Whether YOUR engine is more susceptible to catastrophic failure with low viscosity oil has a lot to do with its age, how it's driven, the brand of oil, how hard its working, oil change frequency, driving environment, etc. This is to say there is NO WAY of predicting whether your engine will enevitably fail if you use low viscosity oil.
However, it is fair to say that as an engine ages, it wears, and as it wears tolerances between moving parts change. These changes are usually increases in the gaps between shafts and bearings, and all the other moving parts within your engine. Is it also fair to say lower viscosity oils will have a hard time dealing with these increased tolerances? As stated earlier, there are many factors that come into play.
So notwithstanding all the online debate about whats to blame, I apply some simple logic to guide my opinion.
1) It is known that higher viscosity or "heavier" oils do in fact provide better protection under most conditions.
2) Your engine can operate with higher viscosity oil just fine.
3) Replacing a blown engine will cost you THOUSANDS if not TENS OF THOUSANDS of dollars.
With this in mind, I lean towards increasing oil viscosity after the vehicles warranty period has expired. However, it's always your call.
