Can thick oil damage engine?

It's best to use the oil viscosity recommended in the owner's manual, but using a slightly thinner or thicker oil (lighter or heavier viscosity) generally poses no long-term harm.
Takedown request   |   View complete answer on blog.amsoil.com


What happens if your engine oil is too thick?

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.
Takedown request   |   View complete answer on docmotorworks.com


Can you damage engine with wrong oil?

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.
Takedown request   |   View complete answer on machinerylubrication.com


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.
Takedown request   |   View complete answer on yourmechanic.com


Is thinner or thicker oil better?

Engine oil 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.
Takedown request   |   View complete answer on lubricants.totalenergies.com


Pat's Perspectives - Thicker Oil (#2)



Will 20w50 hurt my engine?

Is 20W-50 Oil Bad For My Engine? 20W-50 is not a very popular oil viscosity. In the wrong engine, it can lead to sludge, excess friction, varnish deposits, problems with oil burning and oil pressure, and even affect your engine life.
Takedown request   |   View complete answer on repairsmith.com


Does thicker oil affect performance?

Thicker Oil May Not Flow Quickly Enough

The oil won't form a consistent lubricating film, allowing metal-to-metal contact and wear. His engine was designed specifically to use a lower-viscosity oil, in this case 0W-20.
Takedown request   |   View complete answer on blog.amsoil.com


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.
Takedown request   |   View complete answer on tucson.com


When should I use thicker oil?

There are some circumstances where drivers have used thicker oil in an engine. If, for instance, clearances between engine components have increased, gotten sloppy, a thicker oil can help to fill the void. Within reason, thicker oil maintains a better lubricant film between moving parts.
Takedown request   |   View complete answer on columbiatireauto.com


Can thick oil cause misfire?

did you ever pull your spark plugs and note what brand/spec they are? I don't think I've seen you post what they are. "overfilling engine oil can cause misfire DTC's to be stored in the ECM."
Takedown request   |   View complete answer on audiworld.com


Why is my oil thick?

Oil sludge is the result of oxidation and/or contamination of engine oil. It becomes a thick gel that sticks to engine parts, which blocks or hampers oil flow through the engine. It is important to keep that full flow going to prevent placing additional stress on the radiator and the entire engine cooling system.
Takedown request   |   View complete answer on sundevilauto.com


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.
Takedown request   |   View complete answer on rxmechanic.com


How much overfill oil is OK?

If the oil level is a little above the full mark, that shouldn't cause problems. If it's overfilled by half a quart or more, or foam shows on the dipstick, the best fix is to have the oil drained and refilled to the proper level.
Takedown request   |   View complete answer on cars.com


Is it bad to overfill oil?

It can actually cause significant damage to the engine components and even cause your engine to seize up. If you think you may have an oil overfill, in order to fix it, first you need to confirm that it is indeed overfilled, then begin to drain the excess oil from your oil pan.
Takedown request   |   View complete answer on zeiglerfordesp.com


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.
Takedown request   |   View complete answer on services.totalenergies.uk


Is it OK to put 10W40 in a 10W30?

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.
Takedown request   |   View complete answer on offroadingpro.com


Should I run thicker oil in the summer?

As a general rule, you'll get the best protection in the summer when you use a slightly thicker grade of oil, such as a 10W30 instead of a 5W30. Engines need a thicker oil in the summer months because of the summer heat and its effects on thinning the oil out.
Takedown request   |   View complete answer on bellperformance.com


Is 5w30 oil thicker than 10W30?

Both the oils have similar viscosity at 100 degrees Celsius but 5w30 grade oil will thicken less than 10w30 grade oil in cold climate. This means 5w30 grade oil will flow effectively in low temperatures, whereas 10w30 oil will flow effectively in high temperatures because of the smaller temperature window.
Takedown request   |   View complete answer on differencebetween.net


Is 20w50 good for high mileage?

Castrol® GTX® High Mileage 20W-50 is specially formulated for vehicles with over 75,000 miles. It contains Phosphorus Replacement Technology, which reduces the level of phosphorus and replaces it with a proprietary additive that preserves your emission system while maintaining robust wear protection.
Takedown request   |   View complete answer on castrol.com


Is 5w30 better than 10w40?

The 5w30 oil will flow better at low temperatures than the 10w40 oil. This means that the 5w30 oil will protect the engine better at low temperatures, usually when the engine is just starting or during weather conditions such as winter.
Takedown request   |   View complete answer on theydiffer.com


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.
Takedown request   |   View complete answer on repairsmith.com


Is 10w30 thicker than 10w40?

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.
Takedown request   |   View complete answer on motorstate.com


Can I put 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.
Takedown request   |   View complete answer on motorverso.com


Can I use 20w50 instead of 5W30?

A 5W-30 oil is commonly used in passenger cars for normal use throughout the year. A 20W-50 oil will not protect a car as well in a cold winter and its greater viscosity will increase drag and friction in a passenger vehicle.
Takedown request   |   View complete answer on facebook.com
Next question
What are 20 years called?