0W-20 vs 5W-30 Engine Oil
Reviewed by GarageDex editorial
0W-20 flows more easily when cold and is thinner at operating temperature; 5W-30 is thicker at both. Use whichever your owner's manual specifies. They are not freely interchangeable.
| 0W-20 | 5W-30 | |
|---|---|---|
| Cold-start flow | Better (0W) | Good (5W) |
| Thickness when hot | Thinner (20) | Thicker (30) |
| Fuel economy | Slightly better | Slightly lower |
| Typical use | Modern Toyota, Honda, Subaru | Many GM, Ford, older engines |
The first number with the W is the cold rating: 0W pours at a lower temperature than 5W, so 0W-20 protects better on a freezing morning. The second number is how thick the oil stays once hot: a 30 is thicker than a 20, giving a slightly stronger film in high-heat or towing conditions at a small fuel-economy cost.
Most engines built in the last decade that call for 0W-20 were designed with tighter internal clearances for that thinner oil. Putting 5W-30 in them can raise oil pressure, hurt fuel economy, and on some engines trigger the manufacturer to deny a warranty claim.
Which should you use?
Follow the manual. If it says 0W-20, use 0W-20. 5W-30 is correct only for engines that specify it, where it is the better choice for heat and load.
Frequently asked
Can I use 5W-30 instead of 0W-20?
Only in a pinch and not long-term. They have different cold-flow and hot-thickness ratings; the wrong grade can lower fuel economy and, on engines that spec 0W-20, may affect your warranty.
Is 0W-20 or 5W-30 better for winter?
0W-20. The 0W cold rating means it flows faster at start-up in freezing weather, which is when most engine wear happens.
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