# What Happens When You Replace Engine Oil With WD-40: A Ford Probe Catches Fire
A YouTube creator conducted a destructive experiment by draining the engine oil from a Ford Probe and replacing it entirely with WD-40 to document what happens. The result was catastrophic. The engine seized, overheated violently, and the vehicle erupted into flames, destroying the car in the process.
WD-40 is a penetrating oil and water-displacement spray designed for light lubrication, rust prevention, and unsticking stuck parts. It has a flash point around 500 degrees Fahrenheit and a viscosity nowhere near what modern engines require. Engine oil, by contrast, maintains a protective film between moving metal parts even under extreme heat and pressure. It clings to cylinder walls, pistons, and bearings. WD-40 atomizes and burns off almost immediately under engine operating temperatures.
When the Probe started, the engine initially ran but with zero proper lubrication. Metal-on-metal contact began instantly. Friction generated extreme heat within minutes. The thin spray lubricant couldn't suppress the temperature spike or protect bearing surfaces. Engine knock accelerated the destruction. Within moments, internal components seized from thermal expansion and lack of oil film. The engine block temperature shot upward uncontrollably.
As temperatures climbed past 250 degrees Fahrenheit, the WD-40 began smoking and igniting. Flames erupted from the engine bay. The fire spread rapidly through the engine compartment, consuming wiring, fuel lines, and plastic components. By the time the test ended, the Probe was fully engulfed.
This stunt illustrates why engine oil specifications exist. Modern engines demand oils meeting specific viscosity grades, measured in numbers like 5W-30 or 10W-40. The "W" denotes winter viscosity. The second number shows the oil's thickness at 212 degrees Fahrenheit. These properties determine how well oil flows through narrow passages and maintains pressure at operating temperature. Engine manufacturers spend millions testing and certifying oils to ISO and ACEA standards. Vehicles need that precision.
Using WD-40 as engine oil violates every engineering principle. The spray contains mineral oil suspended in volatile solvents that evaporate under normal driving conditions. It provides zero thermal stability, zero anti-wear protection, and zero detergency. Run any engine on WD-40 and you'll experience catastrophic failure within minutes.
The experiment carries value beyond the spectacle. It demonstrates why fuel systems, cooling systems, and lubrication systems operate as integrated units. An engine produces roughly 400 to 600 horsepower in modern applications through controlled explosions inside cylinders. That power generation creates friction, heat, and pressure that only proper oil can manage. Skip the oil or use the wrong fluid, and combustion temperatures and mechanical stress turn the engine into a bomb.
The Probe eventually burned to a total loss. Junkyard beaters make perfect test subjects because they're already destined for recycling. But the lesson applies everywhere. Maintenance specifications exist because engineers learned hard lessons decades ago. Cut corners with fluids or intervals, and your engine will punish you the same way that Probe did.