Changing oil grade? Y/N?

[GTXT23]

Ive followed oils , brands , grades etc for decades and seen many changes . As well heard many people suggest that changing the grade is good in a CX5 N/A for example ...from the current 0W-20 to a 5W-30 / which we see recomended in the turbo 2.5 and 2.5n/a in countries outside the US.
This is in my opinion a major decision to make and thus should be supported by facts that are scientific and obviously dont void the warranty. Ive read some that make the change say because , "my engine is much quieter" , or "dont use 0W-20 in the NA because is a predicate of " CAFE " regulations and is to thin to protect the engine properly " others cite why other countries get 5W-30 recomended on what appears to be the exact same vehicle .
So whats best ? I personally have an N/A 2.5 - 2023 and its uses 0W-20 in the US- Im sticking with that and have many reasons why. I looked for a good video which contains up to date scientific information on multi-grade oils and has tested data why they have reached their conclusions, and recomendations. Also they have a direct comparison to the difference between 0W-20 and 5W-30.

I choose this video for these reasons , and because they use a current 6.2 liter C8-N/A Corvette engine with ...get this ...Cylinder Deactivation !!! A close engine tech wise to the Mazda 2.5 N/A but obviously 4 cylinders shy . Its a good sign GMs top sports car has CD in its NA as a testament to its fundamental reliability and usefullness in fuel savings ..even on a 495bhp performance engine !
Please feel free to comment and interpret the findings and/or add why you use a specific grade oil either recomended or not.

Will Thinner Oils Damage Your Engine?

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m.youtube.com

 

[theblooms]

Great video. And he said it like 10 times, so I'll say it again:

Use What Your Owners Manual Recommends

In my Mazdas, that's 0W-20.

 

[Conrad 16.5]

Great video. And he said it like 10 times, so I'll say it again:

Use What Your Owners Manual Recommends

In my Mazdas, that's 0W-20.

Unless you're in another country...

 

[N7turbo]

With respect to Jason, there are reasons all of these people are going to defer to the owners manual, and it means we aren't going to get a straight answer to the question. You need someone like Project Farm for that.

 

[theblooms]

Unless you're in another country...

Physical location has nothing to do with it. You *still* use what's recommended in your Owners Manual.

 

[Conrad 16.5]

Physical location has nothing to do with it. You *still* use what's recommended in your Owners Manual.

Physical location does have something to do with it, at least to Mazda. If it didn't why then does Mazda have different oil recommendations, for the same vehicle, in different parts of the world?

 

[theblooms]

Physical location does have something to do with it, at least to Mazda. If it didn't why then does Mazda have different oil recommendations, for the same vehicle, in different parts of the world?

Because it very well could be different. Unless you had a hand in engineering the car, you cannot truly know. For instance, some areas get diesels or different displacements than others.
So again, use what you owners manual says.

 

[madar]

In the end, it's a "recommendation", that's all the manual says. I don't see a right or wrong here. Nothing that says a reasonably different grade for your temperature range will cause damage. BITOG website has a lot of useful info on the subject.

 

[Buzzman12]

Wow. Can't believe some of you are taking this so seriously.
Use what makes you happy. Full synthetic, synthetic blend or dino oil? The engine won't really care.
When was the last time you heard about 2.5 NA engine imploding because someone ran 5W30 in North America? Answer: never.
I'm in good old frigid Canada and run 5W30 in my 6. It's happy and I'm happy.

 

[N7turbo]

Physical location does have something to do with it, at least to Mazda. If it didn't why then does Mazda have different oil recommendations, for the same vehicle, in different parts of the world?

Regulations. It's the same motor everywhere.

For example, in JP Toyota uses 0W-8 oil. In the US, they use 0W-16. That could change and they would have to update their manuals.

 

[N7turbo]

Use what makes you happy. Full synthetic, synthetic blend or dino oil? The engine won't really care.

It definitely will. But that's a different subject than viscosity, which is what is being discussed here.

5W-30 will objectively protect your engine better than 0W-20 due to its viscosity. This is really important for turbo motors, less so for the NA motor. The oil in the turbo motor will get hotter and needs the viscosity protection (oil breaks down and thins out at high temperatures).

0W-20 produces less drag. Less drag, more friction. Pick your poison. The 2.5G motor was designed for this and will do fine. Maybe use 5W-30 if you live in a climate that is just always hot, like near the equator.

0W-20 would be more desirable this week here in Nebraska because we are experiencing temps below zero. Sometimes as much as -20°F, the limit of 5W oil. If you're using a 5W-30 you can help this by using an oil with the best cold flow ability:

 

[dunhillmc]

A 6.2L high performance corvette engine is nowhere near being a close match to a Mazda 2.5L NA engine, regardless of cylinder deactivation

 

[cz5gt]

oh no , another oil thread Its getting fun just watching the comments and the youtube ads videos. Just change oil regularly and dont use any weird viscos , stick to 0w20 and 5w30 should be good enough. And likely nobody will keep the car after 160-170k as thats the trend nowadays.

 

[GTXT23]

Wow. Can't believe some of you are taking this so seriously.
Use what makes you happy. Full synthetic, synthetic blend or dino oil? The engine won't really care.
When was the last time you heard about 2.5 NA engine imploding because someone ran 5W30 in North America? Answer: never.
I'm in good old frigid Canada and run 5W30 in my 6. It's happy and I'm happy.

The question is : "when was the last time you heard about 2.5NA engine imploding because someone ran 5W30 in North America......" The answer ... Just because " you " never heard about it dosent mean it has not occured ...furthermore , it also does not exclude other types of damage to the engine ... yet it also does not mean that it has occurred...if there is no legitimate documentable evidence to show that.... ...but sticking with the scientific data we have access to ...better known as " facts " or the " truth " is usually the safest , best bet when trying to maintain a major investment such as your automobile ...and of course the reason I posted this in the first place was to address information read in this forum , and opening up an educational discussion about second guessing the engineers and going on gut feelings, sounds , rumors or a mythological belief system instead of available data- please feel free to post data that supports your belief about this -

 

[GTXT23]

oh no , another oil thread Its getting fun just watching the comments and the youtube ads videos. Just change oil regularly and dont use any weird viscos , stick to 0w20 and 5w30 should be good enough. And likely nobody will keep the car after 160-170k as thats the trend nowadays.

- Thats pretty much the conclusion reached by the data -- so are you using 0W-20 or 5w-30 ? and why ?

 

[Buzzman12]

The question is : "when was the last time you heard about 2.5NA engine imploding because someone ran 5W30 in North America......" The answer ... Just because " you " never heard about it dosent mean it has not occured ...furthermore , it also does not exclude other types of damage to the engine ... yet it also does not mean that it has occurred...if there is no legitimate documentable evidence to show that.... ...but sticking with the scientific data we have access to ...better known as " facts " or the " truth " is usually the safest , best bet when trying to maintain a major investment such as your automobile ...and of course the reason I posted this in the first place was to address information read in this forum , and opening up an educational discussion about second guessing the engineers and going on gut feelings, sounds , rumors or a mythological belief system instead of available data- please feel free to post data that supports your belief about this -

I watched the video that the OP posted about, and most of the conversation is about improving engine efficiency by using a thinner oil. The gain may only be as little as half a percent. It is about meeting stiff MPG criteria in the U.S (CAFE). His concern, and the reason for the video, was that a thinner oil might not provide the protection that a higher viscosity oil provides.
This to me says everything you need to know. It verifies why Mazda recommends 0w20 in North America, and 5W30 everywhere else. I'm pretty confident that either grade of oil is not going to destroy the Mazda engine, so you are free to use whatever you want. Whatever makes you happy I guess.
Personally though (and it is a personal choice at this point), I have not heard a single compelling argument to convince me to go back to using 0W20. Just the opposite actually.

 

[Buzzman12]

5W-30 will objectively protect your engine better than 0W-20 due to its viscosity. This is really important for turbo motors, less so for the NA motor. The oil in the turbo motor will get hotter and needs the viscosity protection (oil breaks down and thins out at high temperatures).

0W-20 would be more desirable this week here in Nebraska because we are experiencing temps below zero. Sometimes as much as -20°F, the limit of 5W oil. If you're using a 5W-30 you can help this by using an oil with the best cold flow ability:

There's always 0W30 out there. I ran that one winter ago. The first number helps on cold startups, while the second number helps when it's up to temperature.
I had Mazda dealers install both 0w30 and 5w30 in my car, and they had no issue with it.
It did not void the warranty either.

 

[cz5gt]

- Thats pretty much the conclusion reached by the data -- so are you using 0W-20 or 5w-30 ? and why ?

me? I am using whats in the manual for my car at least till the powertrain warranty expires. And I religiously change every 6mo or 5k miles whichever comes first just because I want to.

After warranty is out...who knows... likely I would sell the car by then. Rarely keep anything beyond 6 years and the CX5 is nothing special in reality. Another CUV city hauler like the Rav4, CRV, Rogue,etc. Plus its getting overpriced lately without getting anything new.

 

[jadmt]

me? I am using whats in the manual for my car at least till the powertrain warranty expires. And I religiously change every 6mo or 5k miles whichever comes first just because I want to.

After warranty is out...who knows... likely I would sell the car by then. Rarely keep anything beyond 6 years and the CX5 is nothing special in reality. Another CUV city hauler like the Rav4, CRV, Rogue,etc. Plus its getting overpriced lately without getting anything new.

yup that is what I do. follow the owner's manual on oil weight and change the first couple changes early and then go to 5000 miles. it has served me well for 50 years. In the old days I would change about 1000-2000 miles but oil is better now days. I agree nothing special about the cx5 in fact I am a little meh about it. I drive a Ram and the CX5 is my wife's car. It replaced a CRV that was totaled and we could not find a CRV at the time and one of my daughter's has an CRV and they might be nicer cars. I do like the transmission better but other than that I think the CRV is a nicer car.

 

[GTXT23]

yup that is what I do. follow the owner's manual on oil weight and change the first couple changes early and then go to 5000 miles. it has served me well for 50 years. In the old days I would change about 1000-2000 miles but oil is better now days. I agree nothing special about the cx5 in fact I am a little meh about it. I drive a Ram and the CX5 is my wife's car. It replaced a CRV that was totaled and we could not find a CRV at the time and one of my daughter's has an CRV and they might be nicer cars. I do like the transmission better but other than that I think the CRV is a nicer car.

Yeah CRV or Rogue -- Just dont buy a turbo -- big issues -- major maintenance issues -- super low resale value , high insurance -- etc etc -- good call !!