Updated at: 20-03-2022 - By: micdot

This article contains affiliate links. Using any of the links on this page will allow me to earn a small commission at no additional cost to you. Is it possible to combine different oil weights? Asking if two oils of differing viscosities can be mixed is implied. Have you ever combined two different kinds of spirits??? How did the cocktail taste and feel to you?

According to the reviews, it’s brutal. Can we now conclude that combining oils of varying densities can have negative consequences?

No, but here are some things to keep in mind when mixing oils with varying viscosities.

Why Is Oil Very Important In Cars?

Metallic rotors in every car require regular lubrication to keep them in good working order. The only method to maintain these metals lubricated, free of rust, and operating as expected is to use oils. ‘ If oil isn’t pumped into a vehicle or machine’s engine on a regular basis, it will eventually break down. However, your car’s engine’s long-term efficiency depends on the sort of oil you use. Because some oils are better for your engine than others, your vehicle’s maker will always tell you what to use in your vehicle.

Even yet, it may be tough to stick to the oil that has been advised for a variety of reasons. To make matters worse, you may find yourself in a situation where you have little choice but to combine different oils or use an oil that is incompatible simply to get by. However, you should be aware of the many types of automobile engine oils that your vehicle need to operate.

Types of Car Engine Oils

Mineral/regular oil, semi-synthetic oil, and full synthetic oil are just a few of the many varieties of engine oils available. They all have their own perks and drawbacks, and they all cost a different amount of money. Vessel weight is used to measure the viscosity of oil and varies widely depending on the type of additive. The usage of a mixture of engine oils is generally safe, but there are several considerations to keep in mind should you unwittingly set yourself up for a serious engine breakdown.

Can You Mix Different Weights of Oil?

In general, synthetic and semi-synthetic oils are interchangeable, however the additives vary from one manufacturer to the next. As a result, there is no “known” harm done to your car’s engine or other metallic components when these two types of oils are mixed. Even though your engine would operate smoothly with this mix, the amount of time between “oil changes” may be reduced. Car engines can benefit from “Mineral Oils,” regardless of their make or model. Mineral oils, on the other hand, all come from the same source: petroleum. Mixing different weights of oil may not be as effective as using just one oil on a regular basis because of the differing levels of additives in each oil.

As a result of the oil’s near-identical molecular composition, different viscosities don’t separate or react adversely. It is absolutely safe to mix different weights of oil, according to various car engine oil manufacturers. Since the viscosity of 5W30 oil is lower than that of the 10W40 oil, mixing the two produces an oil with viscosity characteristics that are thicker than 5W30 but thinner than 10W40. This oil will not hurt your engine in any way. Even though the viscosity properties have been re-balanced, this does not mean that the oils are incompatible. What’s your rationale for combining oils, anyway? Is there an emergency or is there a lack of regular oil? You won’t gain anything by combining different types of oil or varying the amount of oil you use. Your car’s engine usually functions as expected.

What Happens When You Mix Different Types of Oils

To put it another way, synthetic and conventional engine oil can be mixed without any harm. However, the synthetic oil’s performance will be hampered by the traditional oil, preventing your engine from reaping the full benefits of using synthetic oil. A combination of engine oils from the same manufacturer can also be used; it is completely safe. Synthetic and conventional oils can now be mixed together without a problem.


It’s common for individuals to inquire, “Can you blend different oil weights?” As always, we strongly recommend that you stick with the oil recommended by your vehicle’s manufacturer.