"Are engine oil additives really worthwhile?"
"Will my engine run smoother if I add one?"
"Will it change my fuel economy or acceleration?"
When you look at car accessory stores and online, you'll find a wide variety of engine oil additives for sale.
On the other hand,
Some people say, "Modern engine oils already contain additives, so they're not necessary."
So, what's the real story?
In short, there are various types of engine oil additives, and the approach differs depending on the purpose and usage conditions.
It's important not to simply think, "Adding it will improve performance," but rather to make a decision based on understanding:
"What is it being used for?"
"What performance characteristics does the oil currently in use have?"
"Is it compatible with the vehicle manufacturer's specifications?"
This time, we will explain in an easy-to-understand way what engine oil additives are, their types, roles, benefits, and precautions.
Engine oil itself already contains additives
First, it's important to understand that commercially available engine oil is not just "oil."
Typical engine oil is made by combining
base oil
and
multiple additives.
Additives have various roles.
For example,
-
reducing wear
-
dispersing contaminants
-
inhibiting oxidation
-
suppressing foaming
-
adjusting viscosity characteristics
-
adjusting friction characteristics
-
protecting metal surfaces
These are some of the roles.
In other words, the engine oil you use every day is a product whose performance was originally designed with multiple additives.
The API engine oil certification system also specifies various performance requirements, such as viscosity, shear stability, oxidation, wear, deposits, and low-temperature performance. API-certified oils are formulated to meet these demanding performance requirements.
What are "oil additives" that are added later?
What are generally referred to as "engine oil additives" are products added to the oil already in the engine.
The purpose varies depending on the product.
Typical examples include those aimed at:
-
reducing friction
-
inhibiting wear
-
aiding cleaning performance
-
affecting seal materials
-
addressing oil consumption
-
altering viscosity characteristics
and so on.
Therefore, "oil additives" cannot be evaluated collectively as a single term.
This is because the intended effects vary completely from product to product.
Are engine oil additives worthwhile?
This is probably the most pressing question.
Whether an engine oil additive is "worthwhile" depends on the intended use and conditions.
For example,
If you have a clear purpose, such as "I want to change the friction characteristics,"
"I want to assist with specific symptoms in an old engine,"
or "I want to supplement lubrication performance for a specific application,"
it may be worthwhile if the product design and usage conditions are suitable.
However,
It's not as simple as "just adding it will increase horsepower"
or "it will definitely improve fuel economy."
Modern engine oils are formulated by engine and oil manufacturers to meet specific performance requirements.
Therefore, adding another additive later could potentially alter that balance.
For this reason, the basic principle is to use engine oil of the viscosity and specifications designated by the vehicle manufacturer. The API also advises checking the vehicle manufacturer's recommendations when choosing oil.
Type 1: Friction Reducing Additives
As explained in the article on friction loss, there is a lot of friction inside an engine.
Pistons.
Piston rings.
Camshafts.
Crankshafts.
Bearings.
As these parts move, frictional resistance occurs.
Friction-reducing additives aim to make parts move more smoothly by altering the friction characteristics of metal surfaces.
Generally, components called "friction modifiers" may be used.
If friction is adequately reduced,
-
engine rotation smoothness
-
reduction of mechanical losses
-
impact on fuel efficiency
-
lightness in accelerator operation
and so on, may be related.
However, the actual effect varies depending on the engine structure, the original oil formulation, and operating conditions.
Type 2: Anti-wear Additives
Inside the engine, metal parts move under high load.
When an oil film is sufficiently formed, direct contact between metal surfaces is suppressed.
However, there are situations where the oil film tends to thin, such as immediately after starting or under high load conditions.
Therefore, additives are used to form a protective film on metal surfaces and reduce wear.
Their primary role is to
"protect metal surfaces under conditions where direct contact is likely."
This anti-wear performance is also one of the important original performances of engine oil.
Type 3: Cleaning and Dispersant Additives
Various contaminants are generated inside the engine during combustion.
For example,
-
sludge
-
carbon
-
oxidation products
-
combustion-derived particulates
and so on.
If these accumulate inside the engine, they can affect its operation and oil flow.
Detergents and dispersants play a role in making it difficult for contaminants to adhere to metal surfaces, or in finely dispersing them and keeping them suspended in the oil.
These are also important additives that are included in commercially available engine oils from the outset.
Even the latest API gasoline engine oil specifications require protection against sludge, varnish, and piston deposits.
Type 4: Antioxidant Additives
Engine oil is continuously exposed to high temperatures.
Furthermore, it oxidizes over time due to exposure to air, combustion products, and other factors.
As oxidation progresses,
-
viscosity change
-
sludge formation
-
performance degradation
may occur.
Antioxidants are blended to suppress this degradation reaction.
This also plays an important role in considering the lifespan of engine oil.
Type 5: Viscosity-Adjusting Additives
Engine oils have viscosity ratings such as
0W-20
5W-30
5W-40
Engine oil needs to flow easily at low temperatures and maintain an adequate oil film at high temperatures.
To cope with this wide range of temperature conditions, viscosity index improvers and other additives may be used.
However, caution is needed when adding additives that significantly alter viscosity later on.
If the viscosity deviates significantly from the vehicle manufacturer's specified viscosity, it could affect:
-
engine internal resistance
-
oil pressure
-
oil flow
-
fuel economy
-
starting performance
Therefore, it's important to primarily consider the manufacturer's specified viscosity.
What are the benefits of oil additives?
When an appropriate product is used under appropriate conditions, some products can achieve purposes such as:
-
supplementing friction characteristics
-
supplementing anti-wear performance
-
supplementing engine internal cleanliness
-
addressing specific symptoms in older engines
-
adjusting lubrication characteristics
In particular, from the perspective of friction and lubrication, the accumulation of minute resistances within the engine affects mechanical efficiency.
Therefore, friction control is an important research area for both automobile manufacturers and lubricant manufacturers.
Is it possible that "the engine became quieter" or "smoother"?
After changing oil or adding an additive, some people report that
"the engine sound became quieter,"
"the rotation became smoother,"
or "the accelerator feels lighter."
This is not necessarily surprising.
If lubrication conditions, viscosity characteristics, or friction characteristics change, the movement, vibration, and sound of the machine can change.
However, the actual feeling also depends on the vehicle's condition and operating conditions.
Therefore,
It doesn't necessarily mean that "a change in sound always indicates improved performance."
It is important to separate subjective feeling from measured values.
Does adding oil additive increase horsepower?
This is another common question.
Generally, it's unlikely that adding an oil additive alone will significantly increase the engine's output from combustion.
However, if frictional losses are reduced,
It is conceivable that "less power is consumed within the engine."
In other words,
It's not about increasing the power generated by combustion,
but rather,
reducing the power that is lost.
This is deeply related to "friction loss" which was explained in the previous article.
When considering a car's performance,
It's not just about "how much power can be generated,"
but also,
the perspective of "how much of the generated power can be used without waste" is important.
What are the disadvantages and precautions?
Oil additives have benefits, but also points to be aware of.
1. Combination with genuine oil and specified standards
Modern engine oils are formulated with a combination of additives to create a balanced performance.
Adding another additive later can potentially alter that balance.
Therefore,
It's best to avoid the idea that "any additive will do."
2. Possibility of viscosity change
Depending on the product, adding it may change the overall viscosity characteristics of the oil.
If the viscosity deviates significantly from the manufacturer's specified viscosity, it may fall outside the lubrication conditions assumed in the engine design.
3. Overuse
More is not necessarily better when it comes to additives.
Each product has a specified usage amount.
It is essential to always check the manufacturer's instructions for use.
4. Do not try to fix malfunctions with additives
For example,
-
if there is a loud abnormal noise
-
if oil consumption has increased rapidly
-
if the oil pressure warning light comes on
-
if white or blue smoke is emitted
-
if there is a metallic sound
If you experience any of these symptoms, an inspection is required before adding any additives.
It is not appropriate to try and fix mechanical failures with additives alone.
Are oil additives necessary for new cars?
New cars are designed to meet the necessary performance requirements simply by using the manufacturer-specified oil at the appropriate change intervals.
Therefore, it's not always necessary to add additional oil additives to a new car.
Rather,
-
specified viscosity
-
specified standard
-
replacement interval
It is more important to adhere to these.
The API also advises checking the vehicle manufacturer's recommended performance level when choosing engine oil.
Are they useful for older cars?
For cars with high mileage or those that have aged, the conditions differ from new cars.
Internal clearances, seals, oil consumption, and other conditions may have changed.
Therefore, products designed to address specific symptoms may be helpful.
However,
It's not about "just adding an additive because it's an old car,"
but rather,
it's important to first understand the vehicle's condition.
If there are any abnormalities, maintenance should be prioritized.
Which should be prioritized: engine oil change or additives?
The basic rule is to change the engine oil.
No matter how good an additive is, it cannot make degraded oil last forever.
Engine oil degrades due to factors such as:
-
oxidation
-
heat
-
combustion products
-
moisture
-
fuel dilution
Therefore,
"First, change the appropriate oil at the appropriate interval."
After that,
"Consider additives according to your objective."
This sequence is fundamental.
Who should consider oil additives?
For example,
For those who want to "delve deeper into friction and lubrication,"
"pursue a more detailed feel of the vehicle,"
or "supplement lubrication characteristics according to their operating environment,"
oil additives can be an option.
On the other hand,
We do not recommend using them if you "don't know what you're putting in"
or "haven't checked the manufacturer's specified oil."
It's important to first understand your current oil and vehicle condition.
"Lubrication and Friction" as envisioned by Next Science
At Next Science, we consider "friction and lubrication" to be one of the critical research areas when evaluating the performance of vehicles and machinery.
Not all energy generated by an engine is used for propulsion.
Along the way,
friction.
heat.
drivetrain loss.
Energy is lost in various forms.
What becomes important there is not just
"how much power can be generated,"
but also,
"how efficiently the generated power can be used without waste."
Oils and additives are also part of this larger theme of "how to manage energy loss."
Next Science, including our SPIN series, researches the fundamental movements of machinery from the perspective of friction and lubrication.
Summary: For oil additives, it's important to "understand the purpose and use them"
There are various types of engine oil additives.
Friction reduction.
Wear prevention.
Cleaning.
Antioxidant.
Viscosity adjustment.
Each targets a different effect.
And it's important to remember that modern engine oils themselves are originally designed with a combination of multiple additives.
Therefore,
To the question, "Are oil additives worthwhile?"
The appropriate answer is:
"It depends on the purpose, the product, and the vehicle's condition."
First, use the manufacturer-specified oil correctly.
Then, check the vehicle's condition.
After that, clarify what you want to improve and choose an additive.
This order is important.
When considering engine performance,
Not just horsepower and torque,
friction.
lubrication.
friction loss.
And how the generated energy is used.
By looking at these aspects, you can gain a deeper understanding of how a car runs.