What grade oil do you prefer?

[banjos-n-beer]

I know it comes with 0W-20 in USA, but I am thinking of switching to 5W-30 at the 5,000 mile oil change interval. An oil change video on YouTube by a Mazda tech on a CX90 convinced me it’s probably the correct path to go. I also used 5W-30 in my QX70 with good results.

Thoughts?

 

[Boland01]

We live in Houston so 95% of the year it's hot. My next oil change I'm going to use 5W-30. I saw that same You Tube video and it convinced me to try it.

 

[BoomerZoomr]

I normally always follow the owner's manual where an engine is concerned. I don’t care for this trend towards 0W oils, but would probably follow the manual's recommendations. I don’t know enough about the design of these engines to deviate from the suggested oil. I would definitely use a quality full synthetic oil. Luckily, both my Mazdas use 5W-30.

 

[Mazdiod2]

I'm pretty sure the type, brand, and formulation are all important things to consider over the basic grade to use, either 0w20 or 5w30, which are pretty close.

 

[SparkYellow]

Thought this was the clip but dude didn't say much about why he went with 5w30.

I used 5w30 in my CX-3 once or twice and noticed no difference. What are the benefits for Skyactiv engines? For two of my other cars, thicker is recommended for the summer (20w50/10w40, 5w40/5w30) and for their oil-burning tendencies.

 

[banjos-n-beer]

This is the video. He talks about how Mazda mandated 5W-30 in all turbo engines. They only recommend 0W-20 if it has Moly. My local Mazda dealer buys 0W-20 in bulk and its not the same thing. When I asked them about 0W-20 with Moly years ago after I bought my 2016 CX5 they had no idea what I was talking about. That didn’t inspire confidence. He talks about oil grades near the end of the video.

 

[SparkYellow]

This is the video. He talks about how Mazda mandated 5W-30 in all turbo engines. They only recommend 0W-20 if it has Moly. My local Mazda dealer buys 0W-20 in bulk and its not the same thing. When I asked them about 0W-20 with Moly years ago after I bought my 2016 CX5 they had no idea what I was talking about. That didn’t inspire confidence. He talks about oil grades near the end of the video.

Edit: Idemitsu IFG3 5w30 is available on Amazon, but it doesn't claim moly explicitly.

Thank you for the link! This is the level of instruction I'd expect from a school.

Moly is available as an additive. I used Liqui Moly's anti-friction treatment regularly in my NA R56, less for fuel economy, but more for protection. It is also widely used at track events. I believe all LM oils are moly infused, at different levels, and they are available from Amazon and Napa stores. Zepro/Idemitsu is also moly enriched but I haven't seen them around in the last few years.

The best mpg I have achieved after 150K+ miles is with Royal Purple 0w20. Will try their 5w30 next.

I never knew that the oil supplied by the dealership during oil changes is not the same as OEM oil for sale in quarts. Was the difference evident in lower mpg or by oil sample analysis?

 

[N7turbo]

Hot climate and/or turbo = 5W30

Everything else is discretionary. It's fine to use 0W20 in most cases.

 

[banjos-n-beer]

Hot climate and/or turbo = 5W30

Everything else is discretionary. It's fine to use 0W20 in most cases.

Agree. But it seems like 0W-20 is suggested in the US just to eke out a fractionally larger MPG rating. Most of the rest of the world uses 5W-30.

I haven’t had a turbo engine in 20 years. Don’t remember what I used way back then.

 

[banjos-n-beer]

Edit: Idemitsu IFG3 5w30 is available on Amazon, but it doesn't claim moly explicitly.

Thank you for the link! This is the level of instruction I'd expect from a school.

Moly is available as an additive. I used Liqui Moly's anti-friction treatment regularly in my NA R56, less for fuel economy, but more for protection. It is also widely used at track events. I believe all LM oils are moly infused, at different levels, and they are available from Amazon and Napa stores. Zepro/Idemitsu is also moly enriched but I haven't seen them around in the last few years.

The best mpg I have achieved after 150K+ miles is with Royal Purple 0w20. Will try their 5w30 next.

I never knew that the oil supplied by the dealership during oil changes is not the same as OEM oil for sale in quarts. Was the difference evident in lower mpg or by oil sample analysis?

I didn’t own it long enough to have the oil tested. But I’ve never been that anal or curious about that level of detail. Some people get really into that stuff though. For each their own.

 

[RJB84-Datil]

I just ordered some 0W-20 Castrol GTX, 3 5 Gal jugs from Amazon. I'll probably throw in a bit of 5W-30 for the last quart.

 

[N7turbo]

I just ordered some 0W-20 Castrol GTX, 3 5 Gal jugs from Amazon. I'll probably throw in a bit of 5W-30 for the last quart.

Just as a general note we shouldn't mix different oils because additives are designed in specific ratios as a package due to them interacting with each other. You may unknowingly make the oil additives less effective. This is another reason not to add additives to modern oils.

If it's the same Castrol GTX formula just in different viscosities, then it's not a problem. Don't think you're getting some kind of intermediate viscosity though as I don't think that's how oils work.

 

[Mazdiod2]

I just ordered some 0W-20 Castrol GTX, 3 5 Gal jugs from Amazon. I'll probably throw in a bit of 5W-30 for the last quart.

I thought the turbo uses 5w-30?

 

[RJB84-Datil]

I thought the turbo uses 5w-30?

For the USA, the manual specifies 0W-20, even for the high output Turbo S.
Oil Spec

 

[RJB84-Datil]

Just as a general note we shouldn't mix different oils because additives are designed in specific ratios as a package due to them interacting with each other. You may unknowingly make the oil additives less effective. This is another reason not to add additives to modern oils.

If it's the same Castrol GTX formula just in different viscosities, then it's not a problem. Don't think you're getting some kind of intermediate viscosity though as I don't think that's how oils work.

Yes, it would be the same Castrol GTX, just in 5W-30 instead of 0W-20.
The way I figure it, I would end up with a 1W-22, right .

 

[BoomerZoomr]

That’s interesting that the CX-90 turbo specifies the 0W oil, while the CX-5/CX-50 turbo requires 5W. I wonder how much that is weighted towards what will get the best mileage vs what’s best for the engine. I live in the Deep South… I would feel better about using 0W oil if I lived up North.

 

[N7turbo]

Yes, it would be the same Castrol GTX, just in 5W-30 instead of 0W-20.
The way I figure it, I would end up with a 1W-22, right .

Oil viscosities don't mix like that, you just end up with two different size molecules in your engine.

 

[RJB84-Datil]

Oil viscosities don't mix like that, you just end up with two different size molecules in your engine.

It was a joke.

 

[RobertJT]

There is a video floating around from a dealer mechanic where the guy says use 5w30. Since all my cars and my snow thrower and lawn mower use 5w30 this car, my CX90 , will get 5w30. been using it since the first oil change and no problems. At 15K the dealer did a walk around inspection and said the car was in great shape. Besides when did all the car engines start blowing up. The year all the car makers went to 0W20.