What happens if you put too thick oil in a car?

If the oil is too thick (aka, the viscosity is high), your car may not start in cold temperatures (cold weather places more strain on a vehicle in any case). When this happens, the thick liquid can't properly lubricate every part, and it creates enough resistance to impair the most important function–ignition.
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Will a thicker oil hurt my car?

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 you put 5W30 instead of 10w30?

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. 5w30 and 10w30 engine oils have close viscosity, and thus there is no harm in mixing them.
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What happens if you use 5W30 instead of 5W20?

While both 5W20 and 5W30 motor oils are suitable for high mileage engines, the best viscosity type for your vehicle depends on how the manufacturer designed the engine. Using 5W30 when it is advised that you use 5W20 can result in your vehicle not getting good fuel economy.
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Will 10w40 hurt a 5W30 engine?

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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Thin or Thick engine oil isn't safe!?



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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How do I know if I put the wrong oil in my car?

Signs You're Using the Wrong Oil
  • It Struggles to Start in Cold Weather. If the oil is too thick (aka, the viscosity is high), your car may not start in cold temperatures (cold weather places more strain on a vehicle in any case). ...
  • It Leaks Oil. ...
  • It Smells. ...
  • It Loses Fuel Efficiency. ...
  • It Gets Noisy.
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Can you put 10w30 in a 5W20 engine?

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 good for high mileage?

Amazon Basics Full Synthetic is the best 5w30 oil for high mileage vehicles. This oil should only be used on vehicles exceeding 75,000 miles. This motor oil is formulated for longer drain intervals. It helps in preventing a build-up on drain intervals and preventing rust and corrosion.
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Can you put 10w40 in a 10w30 engine?

Mixing 10W30 with 10W40

Some say that mixing them is fine as long as you don't live in freezing weather. Even if you put together synthetic and conventional blends of these motor oils, they show no harm to your vehicle. However, this is true only if you mix in a quart of the other type to your usual engine oil.
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Can you mix 5W 30 and 10W-30?

It is still not a good idea to mix two different brands of oil, even if they have the same viscosity. The oil you use should be the grade recommended by your car manufacturer. However, if you mix two different brands of motor oil, you could damage your vehicle.
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Whats thicker 5w30 or 10w40?

Main Differences Between 5w30 and 10w40

The 5w30 oil is much thinner than the 10w40 oil and on the other hand, the 10w40 oil is much thicker than the 5w30 oil. The viscosity of 5w30 at low temperatures is 5 whereas the viscosity of 10w40 at low temperatures is 10.
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Can the wrong oil damage your engine?

Using the wrong fluid can cause poor lubrication, overheating, and possibly transmission failure. A mechanic might not be able to reverse the damage, even by flushing the transmission. Mistakenly adding motor oil or brake fluid can also destroy your transmission.
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What happens if I put 5w40 instead of 5w30?

In practice, this means that each oil is just as viscous at lower temperatures and will remain viscous at -30°C, however 5w40 oil outperforms 5w30 oils at higher temperatures, being effective up to ambient temperatures of 50°C, as opposed to 30°C.
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Can you mix 5w30 and 5w40 oil?

you can mix 5w30 with 5w40, you won't notice much of a difference in regular temperatures, but if you have a high-end, luxury car or performance car, it might be a good idea to use the only 5w40, even in emergencies, as it might cause inconsistencies especially under load which can lead to unwanted damage.
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Will 10W40 hurt a 5W20 engine?

The Ranger said that you can mix 10W & 30W to get 20W, or you can mix 5W20 & 10W40, but you don't want to mix 10W & 30W. The answer is yes, but not straight weights or multigrades.
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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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How do you thin out engine oil?

Adding 2 tablespoons (30 mL) of mineral spirits to the jar will thin out the oil.
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Can thick oil cause misfire?

"overfilling engine oil can cause misfire DTC's to be stored in the ECM." I didnt put these in myself, previous owner did. I'm hoping the previous owner was just an idiot and put the wrong oil in at the last change.
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Why is my oil thick?

Why Is My Engine Oil Thick? The motor oil accumulates coolant, dirt, water, fuel, and other contaminants when it is frequently used. As a result of the intense heat of your car's internal combustion engine, it oxidizes as well. As a result, it becomes sludge, a thick gel-like fluid that can cause serious engine damage.
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Can you mix 5W20 and 5W30?

Yes, you can mix 5W20 and 5W30 oil. However, your engine MUST support it. Both oils should be of the same brand to prevent engine damage and should also be of a similar API service level.
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Is 5w30 oil thicker than 10w30?

The number 30 indicates the thickness of the oil when it reaches operating temperatures. Both the oils have similar viscosity at 100 degrees Celsius but 5w30 grade oil will thicken less than 10w30 grade oil in cold climate.
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Is thicker or thinner oil better?

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. Thick oils are better at maintaining film strength and oil pressure at high temperatures and loads.
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Can thick oil cause low oil pressure?

Viscosity that is too high may produce greater resistance from the oil being pumped, leading to a lack of lubrication in the system and consequently lower pressure.
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