What's the difference in oil viscosity?

Engine oil viscosity refers to how easily oil pours at a specified temperature. Thin oils have lower viscosity and pour more easily at low temperatures than thicker oils that have a higher viscosity. Thin oils reduce friction in engines and help engines start quickly during cold weather.
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Is higher viscosity oil better?

This is important, as engine oils naturally thicken as they cool and thin as they are heated. Thin, low viscosity oils flow easier to protect engine parts at cold temperature. Thick, high viscosity oils are typically better at maintaining film strength to protect engines at high temperatures.
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Is 5W-30 oil thicker than 10w30?

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.
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Which oil viscosity is best?

For very cold weather, a viscosity rating of 5W-30 provides maximum protection. When driving in temperatures running from 0 to 60 degrees Fahrenheit, a rating of 10W-30 offers excellent all around protection. For driving in extremely hot conditions, 20W-50 oil offers the best protection.
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Is low or high viscosity better?

Fluids with low viscosity have a low resistance and shear easily and the molecules flow quickly; high viscosity fluids move sluggishly and resist deformation.
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Engine Oil Codes Explained, SAE (Society of Automotive Engineers) numbers - Oil Viscosity Explained



Is Thicker oil better for older engines?

A: Yes. This is a practical method to improve oil pressure in an older, high-mileage engine. The slightly thicker oil film from the heavier base weight oil - 10W - can help protect worn engine bearings as well.
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Will thicker oil damage my engine?

Using oil that is thicker than recommended may lead to a decrease in fuel economy, a higher load on your engine, and even a shorter life for your engine. Conversely, using thinner, lighter-weight oil than recommended can cause excessive wear and shorter life.
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What happens if I use 10W40 instead of 10W30?

Between a 10W-30 and 10W-40, 10W30 motor oil would run smoother in colder climates while a 10W40 would be more effective in preventing engine wear and tear in warmer temperatures.
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Can I use 10W40 instead of 5w30?

Your vehicle does not use 5W-30 oil. The recommended oil viscosity for your vehicle, according to Kia documentation, is 10W-40. If you drive the vehicle in exceptionally cold weather, well below 32 degrees, you can use 5W-30 oil but even 10W-40 is still perfectly OK to use if outdoor temperatures are below freezing.
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What happens if you use the wrong viscosity oil?

Using the wrong motor oil viscosity, especially if thicker than recommended, will directly affect your car's mileage. This is because critical moving parts, like pistons, move less freely. This adds a load onto the engine and subsequently reduces the car's overall fuel efficiency.
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What happens if I put 10w30 instead of 5w30?

Can I Mix 10w30 and 5w30? Most oils will mix perfectly, provided they have a similar synthetic. Therefore, there is no problem in mixing 10w30 and 5w30 since one will be topping up. Mixing the viscosity of oils will not have any effect on the engine.
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Is it better to use 5w30 or 10w30?

Suitable Vehicle Types. 5W-30 multi grade oil is ideal for private vehicles and light-duty petrol and diesel engines. It also provides a better cold temperature start than 10W-30 oil. On the other hand, the slightly thicker oil,10W-30, provides better lubrication for commercial vehicles and heavy-load engine cars.
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Is it OK to use 10w30 instead of 5w20?

Notwithstanding the recommendations of the car manufacturer, mixing 10w30 and 5w20 will not cause any sort of harm to the engine. However, a few drivers claim that it is safer to combine two multi-grade or straight weight oils, rather than mixing multi-grade with straight weight oils.
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Is 5w30 better for older cars?

5W-20 and 5W30 motor oil are winter viscosity grade oils primarily recommended for older engines and light-duty use. These oils are best utilized in colder temperatures.
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Which oil is thicker 30 or 40?

The higher the number, the more viscous or thicker, the oil is at higher temperatures. This means that at 100oC, 10W30 engine oil has the viscosity of an SAE 30 single grade oil, and 10W40 oil has SAE 40 viscosity. 10W40 oil has a higher viscosity, retaining more thickness than 10W30 as the temperature rises.
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Which is better 5w30 or 5w40?

5w30 can be used by different type of vehicles and in different range of temperatures, but is ideal for colder temperatures. 5w40 is often used in higher mileage engine sand performs better in warmer temperatures.
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How do I choose oil grade?

While there is a mountain of information about the various oil choices, the first step is honestly quite simple: Look in your car's manual. The owner's manual for your car will list its recommended oil weight, whether that's a standard format like 10W-30 or something more unusual.
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Is 10w40 good for high mileage?

Designed for high mileage vehicles

Mobil 1 High Mileage 10W-40 motor oil is recommended by ExxonMobil for use in high mileage vehicles (even those that have used lower quality conventional oils), including: Cars. Trucks.
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What is the best engine oil for hot weather?

There are a few ways to get your car prepared for summer with synthetic oils. If you're capable of changing your oil, you can find synthetics at auto retailers. Look for containers with codes such as 0W-20, 5W-20, and 5W-30. These correspond to specific synthetic oil mixtures approved for standard vehicles.
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Is 10w30 better for high mileage?

10W-30 motor oil makes for a decent high-mileage oil. It gives a better fuel economy while reducing the oil consumption for older engines. Older engines with more than 75,000 miles on them require a thicker oil that will properly lubricate their critical engine parts and prevent oil leaks, sludge, and deposits.
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Which is thicker 10W-30 or 10W-40?

The difference between 10W-30 and a 10W-40 is the high temperature viscosity. Obviously, a 10W-40 is thicker than a 10W-30 at high temperature.
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Is 10W40 fully synthetic?

Semi-synthetic oils such as 10W40 have long been the standard. Their base is refined crude oil, which is then blended with additives.
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What oil is better for older cars?

Monograde oils are still widely available, primarily because they're used in very hot climates, or in heavy-duty applications such as mining or construction equipment. These single-grade oils can be used in 1950s and older cars – generally SAE 30 to SAE 50 – but most owners use multi-grade.
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What's the best oil for older cars?

When you're choosing the best oil for older cars or high mileage engines, there are several criteria you can look at.
  • Pennzoil High Mileage Conventional Motor Oil. ...
  • Castrol GTX Part-Synthetic High Mileage. ...
  • Valvoline MaxLife High Mileage Synthetic Blend. ...
  • Mobil1 High Mileage Engine Oil. ...
  • Amsoil Premium Protection Motor Oil.
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What happens if you put 5w30 instead of 5W20?

If you use 5w30 oil instead of 5w20 when it is not recommended or approved by your owner's manual, it can void your car's powertrain warranty, reduce engine efficiency, and possibly even damage your engine in the long run. Hopefully, this helps!
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