Oil for 2021 Mazda CX-5 Skyactiv 2.5L Turbo

JackCastle

2020 CX-5 GTR
I was told at the Mazda dealership that they do not recommend using synthetic oil in the turbo engines. They said synthetic is more prone to burning oil consumption in the turbo engines especially when you get up around 100k on the motor. They use non-synthetic in the turbos 5W-30. The owners manual seems to confirm this.
 
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2013 Mazda CX-5 Sport FWD Auto
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CX5 2018 GT
I was told at the Mazda dealership that they do not recommend using synthetic oil in the turbo engines. They said synthetic is more prone to burning oil consumption in the turbo engines especially when you get up around 100k on the motor. They use non-synthetic in the turbos 5W-30. The owners manual seems to confirm this.
Clowns :) Of course they will say this. Cheap is the word people like to hear and profit is the word dealerships want to hear.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
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Plano, Texas, USA
I was told at the Mazda dealership that they do not recommend using synthetic oil in the turbo engines. They said synthetic is more prone to burning oil consumption in the turbo engines especially when you get up around 100k on the motor. They use non-synthetic in the turbos 5W-30. The owners manual seems to confirm this.
I wonder how many of its customers would buy this kind of talk by the Mazda dealer?
 
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Toronto, ON
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2021 CX-5 GT Turbo
I was told at the Mazda dealership that they do not recommend using synthetic oil in the turbo engines. They said synthetic is more prone to burning oil consumption in the turbo engines especially when you get up around 100k on the motor. They use non-synthetic in the turbos 5W-30. The owners manual seems to confirm this.

Another reason to never let the dealership touch your car after you buy it, unless it's for warranty purposes.
 
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2020 CX5 Signature
Given that Mazda recommends the more expensive synthetic oil for the non-turbo 2.5L, they must have a real reason for recommending dino oil for the 2.5L Turbo.

Other than folks offering THEIR opinions on why they prefer one type of oil over another, has anyone ever offered a real, engineering reason for this?
 
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2013 Mazda CX-5 Sport FWD Auto
Given that Mazda recommends the more expensive synthetic oil for the non-turbo 2.5L, they must have a real reason for recommending dino oil for the 2.5L Turbo.

Other than folks offering THEIR opinions on why they prefer one type of oil over another, has anyone ever offered a real, engineering reason for this?
See the nearly 60 page report I linked above.

4.4.3 was interesting as it was designed to test ability to control turbo-deposits. 2 out of the 5 randomly selected conventional oils didn’t meet the maximum GF-5 specifications.
 
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2021 CX-5T AWD CE
I’d like more specifics about the Mazda OM “confirming” that conventional oil is recommended (vs synthetic). for the 2.5T. Sounds bogus to me. I haven’t heard of any modern car that makes such a recommendation and Mazda’s oil specs can be satisfied with either conventional or synthetic.

A few very high-performance cars and/or cars with very long OCIs do require synthetic but not any Mazda I’m aware of.

Dealers say the damndest things.

- Mark
 
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Toronto, ON
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2021 CX-5 GT Turbo
Given that Mazda recommends the more expensive synthetic oil for the non-turbo 2.5L, they must have a real reason for recommending dino oil for the 2.5L Turbo.

Other than folks offering THEIR opinions on why they prefer one type of oil over another, has anyone ever offered a real, engineering reason for this?

Dealerships do not have engineers working for them, just mechanics and technicians. Mazda does have loads of engineers, even ones that do research, and they would not recommend dino oil in a modern turbocharged engine.
 
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Pueblo county CO
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CX-5 Sport 16.5 6M
Given that Mazda recommends the more expensive synthetic oil for the non-turbo 2.5L, they must have a real reason for recommending dino oil for the 2.5L Turbo.

Other than folks offering THEIR opinions on why they prefer one type of oil over another, has anyone ever offered a real, engineering reason for this?
I always heard the engineering would warrant synthetic because the turbo is so hot.
 

sm1ke

Work In Progress..
Moderator
Contributor
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Canada
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'18 CX-9 Signature
The owner's manual does not outright specify that synthetic is required, only that the 5W-30 oil has the certs. The initial fill is likely 5W-30 conventional oil from Castrol.

There are plenty of resources out there that explain how a synthetic oil can be better than a conventional oil in a turbo engine, but generally the cost of a good synthetic on sale is not much more than the cost of a good conventional, so many will just pay a little extra without a second thought.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
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Plano, Texas, USA
The owner's manual does not outright specify that synthetic is required, only that the 5W-30 oil has the certs. The initial fill is likely 5W-30 conventional oil from Castrol.
Given the similarity of UOA’s between factory fill on 2.5L and Mazda moly 0W-20 full synthetic oil, the initial fill on 2.5T more likely is full synthetic oil for recommended 7,500-mile OCI on first oil change.
 

sm1ke

Work In Progress..
Moderator
Contributor
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Canada
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'18 CX-9 Signature
Given the similarity of UOA’s between factory fill on 2.5L and Mazda moly 0W-20 full synthetic oil, the initial fill on 2.5T more likely is full synthetic oil for recommended 7,500-mile OCI on first oil change.

0W-20? 2.5T uses 5W-30.

Either way, without testing the initial fill, we won't know for sure. I will assume 5W-30 conventional and you can assume synthetic and we can both go about our days. :)
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
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Plano, Texas, USA
I’d like more specifics about the Mazda OM “confirming” that conventional oil is recommended (vs synthetic). for the 2.5T. Sounds bogus to me. I haven’t heard of any modern car that makes such a recommendation and Mazda’s oil specs can be satisfied with either conventional or synthetic.

A few very high-performance cars and/or cars with very long OCIs do require synthetic but not any Mazda I’m aware of.

Dealers say the damndest things.

- Mark
Yes, Mazda has never recommended conventional oil over full synthetic oil on the 2.5T. That Mazda dealer simply lied to the customer.

Here’s the engine oil recommendation from 2020 Mazda CX-5 Owner’s Manual. Interestingly Mazda recommends 5W-30 oil instead of 0W-20 on the 2.0L / 2.5L worldwide except in the USA and Canada.

B796E7F7-29C7-4F51-B854-72ED1E3D8E6C.jpeg

A3BEB535-F35B-4209-9433-109F7AB4EE1A.jpeg

728AC0F5-EA4E-427D-BE3C-4690F9D7BCB1.jpeg
 

sm1ke

Work In Progress..
Moderator
Contributor
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Canada
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'18 CX-9 Signature
I was told at the Mazda dealership that they do not recommend using synthetic oil in the turbo engines. < This is true. They said synthetic is more prone to burning oil consumption in the turbo engines especially when you get up around 100k on the motor. < This is not true.

The dealer lied to you. While Mazda does not recommend synthetic, Mazda also does not recommend conventional. The only requirement that is specified for the 2.5T engine is 5W-30 oil that meets the API cert. This has not changed since the 2.5T debuted in the 2016 CX-9.

Turbocharged engines typically run hotter than a similar NA engine. A full synthetic oil handles high heat better than a conventional oil. This is usually why most people will choose to use full synthetic over conventional on these engines when presented with the option - plus the longer OCI in some cases.
 
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