can you put 5w20 in a 0w 20 car

[StLuna]

Yes, you can use 5W-20 motor oil in an engine that specifies 0W-20, but it is generally not recommended for regular use, especially in colder climates. The primary difference lies in the oil's viscosity, or resistance to flow, at cold startup temperatures. While both oils have the same viscosity (20) at your engine's normal operating temperature (around 212°F or 100°C), the "0W" part means it is thinner and flows more easily at cold temperatures (as low as -35°F or -37°C) compared to "5W" (rated for about -31°F or -35°C).

Using 5W-20 instead of 0W-20 means the oil will be slightly thicker when you start your car on a cold morning. This can lead to a brief period of increased engine wear because it takes slightly longer for the oil to circulate and reach all the critical components. For most drivers in moderate climates, a one-time top-off with 5W-20 likely won't cause immediate damage. However, consistently using the wrong viscosity can reduce fuel economy, increase engine stress over the long term, and potentially void your vehicle's powertrain warranty if an engine issue arises. The best practice is always to use the oil viscosity specified in your owner's manual.

Factor	0W-20	5W-20	Implication of Using 5W-20 in a 0W-20 Engine
Cold-Temp Viscosity (The "W" Rating)	Thinner, flows better at very low temps (-35°F / -37°C)	Slightly thicker at low temps (-31°F / -35°C)	Slightly slower oil flow on cold starts, potentially increasing wear.
Operating-Temp Viscosity (The "20" Rating)	Same SAE 20 grade at 212°F (100°C)	Same SAE 20 grade at 212°F (100°C)	Same protection once the engine is fully warmed up.
Fuel Economy Impact	Optimized for maximum efficiency	May result in a negligible reduction	Potential for a minor decrease in MPG due to increased internal friction.
Warranty Considerations	Meets manufacturer's specification	Technically does not meet the spec	Risk of warranty denial for engine-related claims if the wrong oil is linked to a failure.
Best Use Case	Standard for modern engines, ideal for cold climates	Acceptable for a temporary top-off if 0W-20 is unavailable	Only for emergency use; switch back at the next oil change.

[McElliott]

Think of it like this: your car's engine was designed for a specific weight of oil, especially when it's cold. Putting in 5W-20 is like wearing a slightly thicker sweater under your coat. It might be okay on a cool day, but on a brutally cold morning, it's not as flexible and makes it harder to move. For your engine, that means it works a little harder on startup. It's fine in a pinch if you're low on oil, but get the right 0W-20 put in at your next change.

[VanClayton]

As a mechanic, I see this often. The main risk is to your engine during cold starts. That 0W oil is engineered to pump instantly. A 5W is a bit slower, leaving bearings and camshafts without optimal lubrication for a fraction of a second longer. Over thousands of starts, that adds up to wear. While it won't blow up your engine, it's not a smart long-term habit. Always follow the manual; those engineers know what they're doing.

[Bailey]

My buddy at the quick-lube place said it's usually not a big deal for a short period, especially if you live somewhere like Florida or Arizona where it rarely freezes. The engines are robust. But he always warns people that if they have a warranty, sticking with 0W-20 is crucial. The dealership could use the wrong oil as an excuse to deny a costly repair down the line. It's just not worth the risk for most folks.

[DeMaverick]

I did this once on a road trip because it was the only option at a small-town gas station. I noticed the engine was a tad noisier for the first minute after starting it the next few mornings. Once I got home, I had my usual shop drain it and put the correct 0W-20 back in. I didn't experience any long-term issues, but it was a good lesson. Now I'm more careful about checking oil levels before long drives.