Today, engine oils are available to purchase on the market for a wide range of different applications. As different types of engines have a variety of requirements, oils differ in term of their properties and this includes their thickness, often referred to as viscosity. For engine oil sold for the automotive industry, the thickness of the lubricant is referred to as the “oil”. As a rule, the best practice for selecting engine oil grade is to always adhere to the recommendation of your original equipment manufacturer (OEM) and the oil thickness they advise using for your specific model and type of vehicle.
However, many motoring experts believe that older engines installed in high-mileage passenger cars can need thicker oil as they age over time. As a result, if a car has covered over 100,000 miles, drivers could potentially use a thicker oil like for example 10W-30, as the thicker oil could provide greater lubrication levels and offer enhanced engine preservation.
In this blog, we’ll explore what happens when thicker engine oils are used in automobiles and explore some of the impacts worth considering.
Should you put thicker oil in an engine with high mileage?
As touched upon earlier, the safest approach is to only use the engine oil type and grade that is been recommended by your vehicle manufacturer. It’s worth noting that a common problem for high mileage engines is oil leaks and that some engine oils that are designed specifically for higher-mileage engines. However, these products are typically more expensive than using other types of oils.
Consequently, many mechanical specialists suggest adding a thicker engine oil to high mileage engines as thicker oils are always less likely to result in leakage. Additionally, motorists can also counter this issue by using an engine oil that has been enhanced with anti-leak additives to mitigate this problem.
What happens when you use an engine oil that is too thick for a vehicle’s engine?
Thinner and thicker engine oils can both have advantages and drawbacks and as a result, should only be selected under suitable circumstances. Employing the incorrect engine oil type can cause various kinds of damage to your engine and can harm its functionality over long-term use.
When you choose an engine oil which is too thick for the engine of a vehicle, it will typically reduce both the fuel efficiency and mileage. The reason for this is because a thicker oil will create more resistance in between the engine’s moving parts and as a result, more fuel will be required for them to move freely.
Can thicker oils prolong the active service life of a high-mileage engine?
Issues of oil pressure are often experienced by older vehicles with high mileage engines due to the wear and tear they endure over time and to age itself.
In such cases, a practical approach that can improve oil pressure is to employ a thicker oil. The reason for this is because thicker products use an oil with heavier base weight, and this can help worn engine bearings remain protected. However, vehicle owners attempting this must take care to make sure that no strange noises, such as knocking, can be heard emitting from the engine after the oil has been switched out for a thicker product.
Are full synthetic oils a good fit for older engine types?
Many consumers are under the incorrect impression full synthetic oils are thin and have lower viscosity levels than regular types of oil making them more prone to causing leaks in engines which are older.
However, this is wrong. Full synthetic oils today are manufactured utilising complex processes and expert formulation which make them highly effective in all different types of automotive engines. Furthermore, many synthetic oils also include additives with anti-leak properties which can make them an even safer solution. As a result, full synthetics are safe to use in older engines.
What will happen if you choose the wrong engine oil weight?
In terms of automotive vehicles, oil weight refers to viscosity or thickness of the engine oil. This viscosity is expressed in grades of oil, like 20W-50 and 10W-30, for instance.
All types, models and makes of engines need a different engine oil grade to function at maximum performance; this specification is dictated by the vehicle’s manufacturer. It cannot be emphasised enough that following this recommendation is critical to keeping a vehicle’s engine in the best condition possible.
However, it is worth remembering that using an oil product that only one-to-two grades lower or higher than the grade specified by the manufacturer is safe in most cases and will not contribute to long term damage.
If the grade is varied too greatly, however, vehicle owners can experience a wide range of unwanted issues including oil leaks, poor lubrication and a lack of fuel efficiency.