by Engine Oil Change in Problematic GM Engines
General Motors is making a small but important change regarding its problematic L87 V8 engine, which has become the center of several lawsuits. Last year, about 600,000 vehicles were recalled in the United States due to this engine, and now a new instruction for dealers has appeared.
This recall was the result of a federal investigation initiated by tens of thousands of owner complaints, explaining the attention even to minor updates.
Transition to a New Oil Type
Until now, part of the recall measures involved using Mobil 1 Supercar 0W-40 oil. Now dealers are switching to Mobil 1 FS 0W-40 oil. This change is significant.
GM is replacing Supercar oil with FS 0W-40 in recalled L87 V8. Both oils share viscosity but differ in chemistry and purpose. FS may slightly boost wear protection over cleaning power.
Cause of Problems and Their Solution
The problem with these engines lies in the possible contamination of connecting rod bearings or crankshafts that do not meet specifications. Vehicles that fail the inspection receive a new engine, while those that pass receive new oil.
According to GM Authority, the switch from Supercar to FS is due to cost and availability. Supercar is more expensive and harder to find. FS is more accessible and cheaper. Although they are very similar, there are key differences between them.
Differences Between Oil Types
Brian Silvestro from The Autopian explained their unique properties in detail. Although both oils have the same 0W-40 viscosity grade, they are designed for different audiences. The Mobil 1 Supercar blend is clearly oriented towards high-performance applications, including for the Corvette and Camaro.
It is designed for track use and aggressive driving, even though it is also approved for daily use. In contrast, the FS blend is positioned as a more versatile option. Mobil describes it as suitable for a wide range of gasoline and diesel engines, emphasizing durability under conditions from “moderate to extreme” driving, rather than pure performance.
Chemical Composition and Protection
The report shows that the FS blend contains slightly higher levels of phosphorus and zinc than Supercar oil. Both are key anti-wear additives, with zinc-based compounds like ZDDP forming a protective film on metal surfaces to reduce friction and component wear. This suggests that FS oil may provide slightly better protection under load.
This change in the service procedure can be seen as the company’s attempt to optimize costs and logistics during a large-scale recall campaign. However, given the history of problems with the L87 V8 engine, even such a seemingly technical detail as the oil brand attracts close attention. The transition to a more accessible and, by some indications, potentially more protective product may be perceived as a practical step aimed at ensuring the long-term reliability of repaired units. The success of this decision will likely depend on whether it leads to a reduction in further engine failures and customer satisfaction in the long term.
