Why 5w-30 Won't Stop Your Engine From Failing

[TrailJustin]

Understanding the problem:​

The documented root of the problem when it comes to the engine failures is debris left from the machine process. But the miss understood part about debris is that it is not the large chunks of material causing the problem. But the fine dust or sand like material that is left over. This material does not get caught in filters and makes its way through the system getting between the bearings and other metal to metal contact surfaces.

Well, how do you get that out? With flushing the block. The simplest way for us at home to do that is to do oil changes often. Especially when an engine is breaking in for the first time. Now if the problem is still occurring and not all trucks are affected there could be multiple manufacturing lines producing engines and let's say if there are 10 lines only 2 lines could be producing the problem. Eventually leading Toyota to not know which specific process is causing the breakdown.

Why People are Switching to 5w-30?​

I see it time and time again come in the Facebook groups people switching to 5w-30 weight oil. And it really boils down to 3 arguements listed below. But let's break down those arguements on why they may be false or may be true.

1. The 5.7 V8 used 5w-30 and it went for over 250k miles
2. 5w-30 oil provides better protection
3. The same engine in other countries use 5w-30

Also shout out to The Motor Oil Geek for putting together these slides from the Data they collect at Speed Diagnostix Oil Test Facility.

The 5.7 V8 used 5w-30 and it went for over 250k miles​

When comparing the two motors when comes to bearing tolerance and more the 5.7 V8 has smaller tolerance gaps. Also when you reference the Toyota Online Owners manual for the 2021 Tundra is specifically calls for 0w-20 oil.

5w-30 oil provides better protection​

Looking at the data above they tested oil by brand and weight using the J300 lab testing. This test to see how the oil breaks down over time. There is a grading system to oil and because of use once and oil falls out of grade it will produce more wear than when it was new.

When comparing the list it shows how many oils in the 0w category from that we can see by brand how many oils in that category pass after the test compared to those in the 5w category. In reviewing this data it is not oil weight that is more important in fact you should the weight the manufacture designed the engine for. But it is more important to choose an oil that is able to stay inside grade to protect the motor.

The same engine in other countries use 5w-30​

While this is true. When you look at the manual for the Tundra or other models they do call for a different weight oil. Well why is this?

In different countries they may be using the same engine or block but it doesn't mean everything else is exactly the same. Build can vary when it comes to EVAP and PCV systems. They also have different rates when add to blow by and other areas were the fuel and oil may mix. Also in the US we use the dexos1 standard which may also vary from country to country. So its not exactly and easy playing field.

For Tundra on US soil, using US oil, and US fuels they recommend 0w-20 oils. So the conclusion is that Toyota has refined their engineering to accept these oils and utilize them fully in the proper manner.

Conclusion​

Studying what we known in the past, what Toyota has release as well as what The Motor Oil Geek and others have stated about this industry problem of motors having bearing issues for me it is safe to say Toyota has got it handled. They are point millions of dollars into the problem and further more the recall in general is causing them a lot of headaches and lost revenue.

Certainly this is not where we all wanted to be. But I do believe the company with a full manufacturing team knows best about the motor they designed.