Difference between a 5w30 and 5w40 engine oil

[bismillah]

Hi everyone, I didn't know in which section put this question and that's why I chose General Maintenance.

I had already asked this question in another topic but we were talking about something else ...

Simple and flat question. What is the difference between a 5w30 and 5w40 engine oil?

I have always known that 5w30 oils are made for fuel economy reasons and that replacing them with a 5w40 is always advantageous to protect the engine. I seem to have understood that this is not the case ..

I often hear that a 5w30 oil protects up to 30 degrees. I seem to have understood that this is not the case ...

thank everyone who would reply

 

[OilReport99]

What is the difference between a 5w30 and 5w40 engine oil?

Hope you weather this, but one is 30 grade, the other 40.

 

[kschachn]

Hi everyone, I didn't know in which section put this question and that's why I chose General Maintenance.

I had already asked this question in another topic but we were talking about something else ...

Simple and flat question. What is the difference between a 5w30 and 5w40 engine oil?

I have always known that 5w30 oils are made for fuel economy reasons and that replacing them with a 5w40 is always advantageous to protect the engine. I seem to have understood that this is not the case ..

I often hear that a 5w30 oil protects up to 30 degrees. I seem to have understood that this is not the case ...

thank everyone who would reply

Are you kidding with this question? You discuss HT/HS in another thread but you’re here asking if a 30-grade oil protects to 30°?

 

[Rand]

Are you kidding with this question? You discuss HT/HS in another thread but you’re here asking if a 30-grade oil protects to 30°?

I guessing it has to do with owners manual saying not to use a 30 above 30degrees celcius.

 

[toneydoc]

The difference is that they both flow the same at start up conditions but that at full operating temperature the 5w40 will be slightly more viscous or thick than the 5w30
I bet that both will work just fine in Italy temps

 

[bismillah]

Are you kidding with this question? You discuss HT/HS in another thread but you’re here asking if a 30-grade oil protects to 30°?

No, I haven't made myself clear.

I said that many (out of ignorance) argue that a 5w30 oil protects up to 30 degrees centigrade as in the graph that is found everywhere ... and that it is used only for fuel economy reasons. For this reason it is always advisable to use a 5w40 oil.

My question is much more advanced.

Having ascertained that it is not a question of ambient temperature: D

I understand that a w40 oil is more viscous when hot compared to a w30 but my question is
what is the difference to the engine?
When a w30 is recommended, what if a w40 is used? pros / cons
Is an increase in hot viscosity always beneficial?

 

[Gimpy1]

Hope you weather this, but one is 30 grade, the other 40.

Soo like 10 bitog units?

 

[kschachn]

No, I haven't made myself clear.

I said that many (out of ignorance) argue that a 5w30 oil protects up to 30 degrees centigrade as in the graph that is found everywhere ... and that it is used only for fuel economy reasons. For this reason it is always advisable to use a 5w40 oil.

My question is much more advanced.

Having ascertained that it is not a question of ambient temperature: D

I understand that a w40 oil is more viscous when hot compared to a w30 but my question is
what is the difference to the engine?
When a w30 is recommended, what if a w40 is used? pros / cons
Is an increase in hot viscosity always beneficial?

By reading other various posts by you especially (again) the ones involving HT/HS, you can answer this.

Are you just playing everyone along?