automobile
For more than a decade, GM truck owners have watched oil viscosity thinner and thinner, mostly in the name of achieving marginal fuel economy benefits. Now the mood is shifting sharply in the other direction. A recent GM Authority reader poll focused on the upcoming next-generation small block V8 shows that most enthusiasts want GM to move back to thicker oil, with 5W-30 leading the votes and 0W-40 right behind. Only a small proportion of respondents wanted to keep the current 0W-20 specification, which says a lot about how high owner confidence currently is.
It’s easy to see why this debate has become so personal for truck people. To meet CAFE goals, GM converted its large truck V8 engines to 0W-20 around the 2020s. The official rationale has always been that modern engines are designed for tighter clearances and advanced oil formulas. On paper it works. But the lifespan of a truck is not a laboratory test. Towing, heat, long highway trips, and heavy accelerating under load are exactly the conditions where owners fear a thinner oil film leaves less room for error, especially as the miles pile up and wear tolerances inevitably increase somewhat.
The focal point was the L87 6.2L V8 recall, which affected a large number of GM’s most popular trucks and SUVs, including the Silverado, Sierra, Tahoe, Suburban, Yukon and Escalade models. Reports surrounding the recall indicate internal engine failures resulting from problems with the rotating assembly, and the solution for vehicles that pass inspection has received the most attention: GM’s guidance includes switching to a higher viscosity 0W-40 oil along with associated replacement parts. This move has fueled the very argument enthusiasts have been making for years, that thicker oil can provide additional protection when temperatures rise and stress remains high. At the same time, it has created a strange divide, with some owners being told that 0W-40 is the safer solution, while others are being warned that their warranty depends on sticking with 0W-20.
Looking forward, GM’s decision for the Gen 6 small block V8 is about more than just an oil cap label. At issue is whether GM will prioritize the last fraction of an mpg in a test cycle or whether it will build the kind of durability confidence that truck buyers expect from years of hauling and towing. The timing is also interesting, as the proposed federal changes could ease some of the pressure that originally pushed automakers toward ultra-thin oils. And GM is already proving it’s comfortable with thicker oil in demanding applications, with factory specs for modern Corvettes calling for higher viscosities under the dexosR performance umbrella. If GM wants the next V8 truck to feel like a long-term keeper, the easiest win might be to listen to the people who actually work on these engines.
FOLLOW US TODAY:
Mike Floyd is a financial manager by profession and a car enthusiast at heart. As a CFO with a keen eye for detail and strategy, Mike brings his analytical mindset to the automotive world, uncovering new insights and unique perspectives that go beyond the surface. His passion for cars – especially his favorite, the Porsche 911 – drives his contributions to ArticleSubmission.news, where he combines his love of performance and design with his professional precision. Whether breaking down industry trends or highlighting emerging innovations, Mike helps keep the site both current and forward-thinking.
