0W-16 vs 0W-20 Motor Oil: What's the Difference and Can You Use 0W-20 Instead?
November 9, 2026 · RPS Distributors
A few years ago 0W-20 was the thinnest oil most shops stocked. Today a growing number of new engines, especially fuel-efficient and hybrid models, call for 0W-16. Both oils look almost identical on the shelf, so customers and techs often ask: what is the real difference, and can one replace the other?
What the numbers mean
The first number with the "W" (the 0W) is the cold rating. Both 0W-16 and 0W-20 have the same 0W cold rating, so both flow very well at start-up in winter.
The second number is the viscosity at normal engine operating temperature. 16 is thinner than 20. The SAE added the 16 grade in 2013 so automakers could use thinner oils to cut friction and improve fuel economy.
| 0W-16 | 0W-20 | |
|---|---|---|
| Cold start flow | Same (0W) | Same (0W) |
| Thickness when hot | Thinner | Slightly thicker |
| Typical use | Newer fuel-efficient and hybrid engines that specify it | Most late-model gasoline cars and light trucks |
| Oil type | Almost always full synthetic | Usually full synthetic or synthetic blend |
Which engines need 0W-16?
Only use 0W-16 when the owner's manual or the oil fill cap calls for it. Many newer Toyota and other fuel-efficient engines specify 0W-16. Always check the manual, because the same model can use different grades depending on the engine and model year.
Can you use 0W-20 instead of 0W-16?
Some owner's manuals allow 0W-20 as a substitute when 0W-16 is not available, often with a note to go back to 0W-16 at the next oil change. Others do not. Check the manual before substituting, especially on vehicles still under warranty. Going the other way, putting 0W-16 in an engine that calls for 0W-20, is not recommended.
Can you mix 0W-16 and 0W-20?
Topping off with a small amount of the other grade will not damage the engine, because both are compatible motor oils. The mix will simply land between the two viscosities. For the oil change itself, fill with the grade the manufacturer specifies.
Tips for shops and parts counters
- Stock both grades. 0W-16 demand keeps growing as newer vehicles come in for service.
- Check the fill cap as well as the manual. Many engines print the required grade there.
- Look for the right approvals on the label, such as API SP and ILSAC GF-6B for 0W-16.
Frequently asked questions
Is 0W-16 better than 0W-20?
Neither is better in general. 0W-16 is right for engines designed for it, and 0W-20 is right for engines designed for 0W-20. Use the grade your manual lists.
Is 0W-16 always synthetic?
Nearly every 0W-16 on the market is a full synthetic, because such a thin grade needs synthetic base oils.
Does 0W-16 improve fuel economy?
Thinner oil reduces internal friction, which is why automakers use it. The gain is small for a single car but adds up across a fleet.
0W-16 and 0W-20 oil we carry
Shop Toyota Genuine 0W-16 Full Synthetic (case of 6 quarts), Mobil 1 Advanced Fuel Economy 0W-16, Idemitsu 0W-16 Full Synthetic 5 Qt and Mobil 1 Advanced Fuel Economy 0W-20, or browse all 0W-16 motor oil and 0W-20 motor oil.
Related guides: Motor Oil Viscosity Explained · Synthetic vs Conventional vs Blend
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