Updated at: 13-03-2022 - By: micdot

Drivers have been combining 5w30 and 5w40 oil in their vehicles. Many motorists, on the other hand, choose not to engage in this activity because they are unsure of the potential outcomes. So, in this post, we’ll examine the effects of mixing 5w30 and 5w40 oil, and whether it’s possible to blend the two. Can 5w30 and 5w40 oils be combined? Yes, it is correct. Mixing a 5w30 with a 5w40 oil is an option. It is, however, never advisable.

Some motorists may be perplexed over whether 5w30 or 5w40 motor oil is the best choice for their vehicle. Owner’s manuals are a great resource if you’re one of these drivers. The best and most appropriate motor oil for your vehicle will be listed in your owner’s manual. It’s common knowledge that you can get good results by combining five-weight and five-weight oil, but it’s not widely known how this can go wrong. The right motor oil is necessary for a vehicle to function and run correctly. The quality of your engine oil can have a significant impact on your overall performance. Good motor oil will help you get the most out of your vehicle’s performance and fuel efficiency. In this section, we’ll examine whether or not combining 5w30 and 5w40 motor oils is hazardous to your engine and what might happen if you do. Please, let’s get the ball rolling!

Can I Mix 5w30 and 5w40 Oil?

To begin, let’s have a look at the names of these oils to get a better understanding of the question. The letter is preceded by certain numbers. The oil’s viscosity is represented by that number.

The letter W stands for winter. For both high and low temperatures, the number after the letter is used to signify the weight of the oil. Viscosity and weight are both measured by numbers before and after the letter W, respectively. The 5w30 and 5w40 oils have the same low-temperature flow characteristics, indicating that they are equivalent. Both have a low viscosity rating of five, which accounts for this. Because of their differing weights, these oils will not be able to be weighed in the same way. In terms of weight, one is thirty and one is forty. As a result, 5w30 and 5w40 oils can now be blended. They don’t cause any harm.

The drawback is that you may not get the full advantages of one oil because you’ve combined it with other components from the other oil. As a result, it is possible to combine 5w30 and 5w40 oils.

Can You Add 5w30 to 5w40 Oil?

You can, in fact, mix 5w30 and 5w40 oils. Both oils, on the other hand, should be made by the same company and have the same formula. This is to ensure that the additive balance is maintained. However, some people have had no choice but to add 5w30 to a 5w40 oil.

Can You Add 5w40 to 5w30 Oil?

5w30 can be added to 5340 oil as well. It’s something that many drivers have already done. Just make sure that both oils are from the same brand and are of the same formulation before you buy them.

Is It Ok To Mix 5w30 and 5w40 – Possible Downsides?

Mixing 5w30 and 5w40 oil is fine. The worst-case scenario is a failure of the engine, however this is highly unlikely to occur. It’s possible that you won’t reap the full benefits of one oil, which is the worst-case situation. This is due to the fact that you’re adding another oil to the current oil. As a result, 5w30 and 5w40 oils can be blended. As a result, no harmful effects will occur.

Many drivers have stated that their engines have not been harmed in any way. But if you can avoid it, it’s generally best to avoid it at all costs. This is due to the fact that no owner’s manual would encourage it, and it is not recommended.

What Happens if You Mix 5w30 and 5w40 Oil?

The two types of oil, 5w30 and 5w40, do not mix completely when mixed together. They’d each go their own way. High-temperature applications call for 5w40 oil. Because the oil used is a blend, you won’t receive the full advantages. The 5w30 and 5w40 oils will flow evenly into your engine’s components at low temperatures. Since there is a chance that the other oil will not fully realize its potential and benefits, this is your sole hope for an upside.

Because of the mix, you won’t get all of the benefits. Because of this, knowing the results of a 5w30/5w40 oil blend is critical. As a result, only use oil from the same brand when mixing. Achieving this ensures that the two oils don’t differ much.


In summary, 5w30 and 5w40 oil can be mixed together. This is possible. Many motorists have already experimented with blending the two types of motor oil. Many car owners are also using a different oil to top off their vehicles. There have been no reported modifications or negative outcomes. As a result, you have the option of combining the two. Any damage to your engine or other parts will be minimal.