0W-20 vs 5W-20 Engine Oil
Reviewed by GarageDex editorial
0W-20 and 5W-20 are the same thickness when hot (both 20); they differ only in cold-start flow. 0W-20 flows better when cold. Many engines that spec 5W-20 can safely use 0W-20.
| 0W-20 | 5W-20 | |
|---|---|---|
| Hot thickness | 20 (same) | 20 (same) |
| Cold-start flow | Better (0W) | Good (5W) |
| Backward compatible | Often replaces 5W-20 | Should not replace 0W-20 in cold |
| Typical use | Newer Honda, Ford, Hyundai | Older Honda, Ford 5.0 etc. |
Because both oils are a 20-weight when hot, they give the same protection at operating temperature. The only real difference is the W rating: 0W-20 keeps flowing at a lower temperature, so it reaches the top of the engine faster on a cold start.
Many manufacturers updated older 5W-20 engines to 0W-20 to improve cold-weather protection and fuel economy. Going from 5W-20 to 0W-20 is usually fine; going the other way in a cold climate is not ideal.
Which should you use?
If your manual lists 5W-20, 0W-20 is almost always a safe upgrade, especially in winter. Confirm in the manual, which often lists both.
Frequently asked
Are 0W-20 and 5W-20 interchangeable?
At operating temperature they behave the same. 0W-20 is the safer swap (better cold flow); replacing 0W-20 with 5W-20 in very cold weather is not recommended.
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