5W-30 VS 10W-30
5W–30 and 10W–30 lubricants have the same viscosity at the operating temperature of the engine. That is usually 100°C (212°F) when the engine is running (in an average engine). However, the 10W–30 oil will be thicker when it is cold. As per API recommendations (1) for car engines, you can use 10W–30 oil if the maximum expected outside temperature is above -18°C (0°F). If you are living in an area where the outside temperature can go below zero; It is better to use 5W–30. Always follow the engine manufacturer’s recommendations.
5W–30 vs 10W–30 at 100°C:
Shown in the video are 5W–30 and 10W–30 engine oils in tubes at 100°C (212°F). A steel ball moving from top to bottom indicates the thickness or viscosity of the oil. At 100°C (212°F), the viscosity or resistance to flow is almost the same for both 5W–30 and 10W–30.
The number 30 in both 5W-30 and 10W-30 indicates the SAE viscosity at 100°C (212°F). That is the operating temperature of an average engine. The number before “W” (5W-XX and 10W-XX) tells the SAE viscosity of the oil when it is cold. W indicates winter or cold and that’s why it is shown here in blue color.
In the example above, 5W-30 has “SAE 5” viscosity and 10W-30 has “SAE 10” viscosity (5W and 10W) when cool. A higher SAE number means that the oil is thicker or has a high viscosity. SAE 10 is thicker than SAE 5, and similarly, SAE 40 is thicker than or has a higher viscosity than SAE 30. Check the SAE Viscosity chart called SAE J300 standard.
So both the oils 5W–30 and 10W–30 have exactly the same viscosity (SAE 30) when your engine is running, and will perform in the same way. However, the 10W–30 oil will be thicker (higher viscosity) than the 5W–30 when it is cool.
“W” relates to winter or cold
Shown in the video are tubes with 5W-30 and 10W-30 lubricants. Both tubes with the steel ball were refrigerated at -18°C for half an hour. Air bubbles are trapped in the test tubes because of the low temperature. The thickness of 10W-30 is much higher, as shown in the video demonstration.
Which is better?
In modern car engines, we need the oil to be thinner at the time of startup. Most experts agree that 80% of engine wear occurs during startup (warming-up) the engine. There is a problem with the thicker oil when the engine is cold. We need the oil to be thinner at the time of starting the engine. The lubricant must reach all parts of the engine right away. However, the problem with thicker oil is that the oil’s resistance to flow is high. Hence, the oil will not reach all around the moving parts of the engine when you turn the key. 5W–30 oil has the same viscosity at 100°C but is thinner when cool. 5W–30 is always a synthetic lubricant. The only problem with 5W–30 is NOACK (evaporation tendencies of a lubricant (engine oil) at high temperature).
Conclusion:
According to API motor oil guide [1], If you are using 10W–30, you can safely switch to 5W–30 (in car engines). 5W–30 is thinner than 10W–30 when cold. (you must follow the manufacturer’s recommendations). However, switching from 5W–30 to economical 10W–30 is not always recommended. According to API motor oil guide [1], you can use the 10w–30 if the lowest expected outdoor temperature is above -18°C and you are following the manufacturer’s recommendations. I am using 5W–40 for my car instead of 15W–40. It is a recommended lubricant along with 15W–40 by the engine manufacturer, even though I am driving in a hot climate in the gulf region. 5W is a synthetic lubricant having better oxidation resistance and longer drain intervals.
Can I use 10W-30 instead of 5W-30?
The only reason to choose 10W-30 is the price. Otherwise, 5W-30 is superior to the 10W-30 for car engines. Better select synthetic 10W-30. You can only switch to mineral 10W-30 if the lowest expected outside temperature is above -18°C (0°F). Always follow engine manufacturer recommendations.
Can you use 5W-30 instead of 10W-30?
Absolutely yes for car engines, 5W-30 is usually synthetic and superior to 10W-30. Both have the same viscosity at the operating temperature of an average car engine. 5W has lower viscosity when cool and is considered better for the car engine during engine start. For high-power diesel engines, follow manufacturer recommendations because of higher NOACK in 5W.
Is 10W-30 thicker than 5W-30?
Both 10W-30 and 5W30 have the same viscosity at 100°C (212°F), it is the operating temperature of an average engine. But 10W oil is thicker or has higher viscosity when cool.
What does the “W” stand for in the SAE viscosity grades?
“W” stands for winter, for example in 5W–30, the lubricant has SAE 5 viscosity when cold and SAE 30 viscosity when the engine is running. There are 2 sets of numbers in 5W–30 separated by a dash(-). The number 30 [3] relates to the viscosity or thickness of the oil when it is at 100°C. It is considered a working temperature for the average engine. The “W” means winter and 5W relates to how the oil performs when it is cool. So 5W–30 is SAE 30 viscosity when at 100°C and SAE 5 viscosity when cool.
References:
(1) Motor Oil Matters by api.org
(2) SAE Viscosity Grades.
I bought oil for my car thinking it took 10w 30 for some reason but on the filler cap it says 5w 30 and i was wondering will this damage my car it don’t uselly get below zero sometimes not much we get some negative numbers a few times during the winter but on the back of the oil container it says it meets the Chrysler standereds which i have a 09 Chrylser Sebring i don’t think this will harm i know in the winter time it may take longer to warm up the oil
5W30 is fine for all weather. I use 5W30 instead of 15W30 in my car.
Is it better to use 5w-30 over 10w-30?
Odometer is over 150k and is for a bmw Mini Cooper S turbo 2007 model.
Troy Bilt super bronco 50 xp riding mower says use 10w30. Ok or not to use 5w30 in northeast Texas? Gets 100+ here in summer, and usually not colder than 30 for long periods (plus not usually running mower in the winter…). Thanks.
Mary, generally it will not affect anything regarding the standard running of your motor – the second numbers are the viscosity (thickness) of the oil at running temperature (about 100°c/212°F).
The first number is the viscosity at startup of the engine. Any engine will be at running temp pretty fast though so as long as the recommended startup grade of oil is thin enough for the engine to kick along happily till it’s warm enough, by time it’s warmed up the oil won’t be any difference anyway…
So even in Texas, once the engine being used reaches 212°F running temp, the oil you want to change to will be the same thing really 👍
Is 5-30 or 10- 40 best for a 2005 Chevy Impala? It it has 188,000 miles
5W-30 and 10W-40 are different lubricants. In my opinion you are safe with 10W-40 if outside temperature in your area is above zero degrees. If you are looking for 5W, it is better to use 5W-40. 5W-40 has same viscosity but more fluid during cold engine start.
10w30 must change after 5K KMs running
Or after 10K KMs
It depends and you must follow manufacturer recommendations. As a guide, synthetic 10W-30 may run 10,000KMs or more if recommended by the manufacturer.
10W-40 has higher viscosity when the engine is running than the 5W-30. Keep using 10W-40 or switch to 5W-40. Read the above article.
Hello my name is Michael I have a question I have a 2004 silverado Z71 I’m using Castrol 10w40 high mileage because I have 265.000 can i go back using 5w30 Castrol Edge full Synthetic
This oil is very helpful to engine work smooth…
Hello
I will like to make an inquiry about your line of Motor Oil. I want to know if you have the below specifications available and also I will need a formal quote regarding it.
I will be looking forward to get a quick response to this. Find below is the specification of the products being requested.
1) 5w-30 Engine Oil….5ltrs (5qrts) Synthetic …..3000 Units
Stay Safe
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Hello,
Thanks for the comment, our sales team will contact you soon.
If you are using 5W-40 instead of 15W-40, what are the benefits/drawbacks of using 5W while driving in hot climate like gulf? Are you following manufacturer recommendations?
5W lubricants are mostly synthetic, Synthetic base stocks have superior performance than minerals base oils. The only drawback for 5W is high noack value that is not a big problem for car engines. Yes 5W is recommended by the engine manufacturer along with 10-40 and 15W-40. My car is now 6 years old and at 205,000 km, it is like new.
Can i use 10w30 synthetics instead of normal 5w30 .lowest temperature here 19C degree .and high temperature of 40C
Yes, you can use fully synthetic 10W-30, But you still have to check owner’s manual to verify the recommendations by the engine manufacturers.