Ford Motor Company just requested a judge dismiss a lawsuit. The case alleges it knowingly designed an F-150 V8 that allows “engine oil to seep into the combustion chamber.” What’s interesting about this case is that Ford had to publicly admit exactly how much oil it’s alright with its engines burning. That’s information you won’t find in any owner’s manual.

Lyman, et al., v. Ford Motor Company

The lawsuit, filed in the U.S. District Court for Eastern Michigan, is called Lyman, et al., v. Ford Motor Company. It pertains to the 5.0-liter V8 Ford installed in 2018–2020 F-150 pickup trucks. It argues the “piston ring assembly and cylinder coating in the Class Vehicles are defective.” Why? Because they aren’t “preventing oil from by-passing the rings.”

The truth is that every engine burns some oil. The nature of the pistons’ movement means they can’t have a perfect seal with the cylinder wall. When oil makes its way into the combustion chamber, it burns alongside the gasoline. Few modern engines burn enough oil for you to notice the level changing between oil changes. If you’ve driven a vehicle with an old, worn-out engine, you know that as the piston rings wear out, an engine will burn more oil. Sometimes, you even need to top it off between changes.

Ford asks judge to dismiss F-150 V8 burning oil lawsuit

When Ford requested a judge dismiss Lyman, et al., v. Ford Motor Company, it made two seemingly contradictory statements. It said the V8s in question don’t burn an excessive amount of oil. But it also said that it modified these trucks to burn less oil.

Ford admitted it has a “minimum criterion for oil consumption for average retail customers based on laboratory/customer correlation.” How much? One quart of oil every 10,000 miles. This number is used to test engines in development, not vehicles on the road. The company “does not quantify expected oil consumption in the Owner’s Manual or other customer information.” Translation: You won’t see it admit that one quart every 10,000 miles is acceptable for a new engine anywhere outside of court.

So Ford is “permitting engine oil to seep into the combustion chamber.” But so are all automakers. It’s just part of an engine’s operation.

One quart is usually the distance between the “full” mark on your oil dipstick and the “add oil” mark. Ford recommends you change an F-150 V8’s oil every 7,500 to 10,000 miles. So if you follow its directions, your V8 should have plenty of lubricant left. But that doesn’t leave much margin for error. An engine that burns one quart every 10,000 miles when new could need a lot of oil between changes as it wears out.

Ford admits it addressed excessive oil consumption in 2018–2020 V8 F-150s

Wait, there’s more. Ford admits that an oil burn issue was potentially caused “when a running change was made to the engine’s valve stem seals (a cylinder head component unrelated to the piston assembly).” It admits it issued a technical service bulletin and new powertrain control module calibration which corrected any excessive oil consumption. It also added it’s not charging owners for this software fix.

So Ford wrote a software patch designed to prevent oil slipping past the piston rings? That’s plausible but a bit suspicious. If the judge decides to hear the entire case, it may be an interesting one.