Mazda responds 5w-30

[madar]

We are all well aware, what's stated in the owners manual is regulated by CAFE for 0.2mpg fuel savings, NOT based on what the engineers designed the vehicle around.

It's helpful to know what the engine is actually specified for, and , to consider the statement: "tight engine tolerances" as complete and utter bull, and to stop worrying about using 5w30 when the engine was clearly designed for weights beyond that. 5w30 is also a weight that was pushed by CAFE not very long ago, actually.

As for actually going beyond 5w30? I'd run 5w40 or even a 10W in hot weather. Done it before, would do it again.

That's not what I'm talking about. I'm talking about the differences between the oil chart from 2016 versus the one in this post. There's a half dozen new oil grades which aren't CAFE oils on your chart. All of a sudden Mazda is giving its blessing for these grades.

 

[CrazyHippie]

go to walmart buy 0w20 get the reciept photo copy it and then return it and get the oil of your choice.

Yep. And if asked, tell the Truth. "I bought 0W-20 for that oil change." Reciprocal honesty is the best policy.

 

[joc1394]

2025 CX-5 2.5T here. My cap says 5w30...
You could find a wrecked turbo and swap caps after you fold over the page in the back of the manual with the oil recommendations for the turbo. My manual has recommendations for both 2.5 N/A and 2.5 Turbo, it would be easy to get confused...

 

[nickswhip24]

go to walmart buy 0w20 get the reciept photo copy it and then return it and get the oil of your choice.

you sneaky dog-thats good

 

[nickswhip24]

The maintenance requirements for severe driving conditions represent a higher standard of care for the same engine. It would be difficult for Mazda to deny warranty coverage on the ground that the owner has been more careful/diligent than most.

eh,i got that from toyota with a 2011 camry-they had sludge problems and i was told i wasn't covered because i did proper maintenance-i changed out 4 oil sender switches ,paid someone to pull the bottom end of engine apart...good oil pressure top and bottom and kept getting low oil light...
i got the car used so i was screwed-yes ...i had all my receipts for self maintenance and still got Nada

 

[yrwei52]

Wow, 10w-50 is in the mix now? Incredible.

Yes, no 10W-50 in the mix in earlier days. Here’s the oil viscosity chart from Mazda CX-5 Owner’s Manual world wide back to earlier days:

 

[Lazy2.5]

Yes, no 10W-50 in the mix in earlier days. Here’s the oil viscosity chart from Mazda CX-5 Owner’s Manual world wide back to earlier days:

View attachment 382543
View attachment 382544

These charts claim that a 0W, 5W and 10W are all suitable for well over 40c+ operation.

My thought process:

- I've verified on Mazdaedit that the target oil temperature for the 2.5 is around 84c - The ECU maintains this target regardless of ambient temp.

However, during sustained WOT in 30C+ weather, oil temp nearly hit 100C, which is high for a thermally efficient engine like the Skyactiv.

Therefore, if you are driving normally, even in hot weather, assuming your oil temps do not creep past 85C, in theory, you should be getting "sufficient" engine protection with a 0W. However, I am still doubtful of this, as temps will easily increase with additional cargo, going up hill, higher RPM and throttle position, etc.

I am further doubtful of 0W in general as we know that is prioritizes fuel economy above everything else and simply leaves owners in the dark regarding how much additional engine wear it causes and whether it is truly sufficient.

Based on the fact that my engine sounded significantly quieter and smoother (Much less valvetrain clatter) When switching to 5w30 years ago, I never went back to a 0W.


Another point to make is cold starts and cold weather driving. People love to argue that 5W and 10W is so terrible for this use, although the chart clearly shows no problems unless you live in the Arctic.

For those of you that like to load the car up with your family, gear, have the A/C blasting, accelerating hard and maintaining high speeds in 30C+ weather during your road trips, I personally would advise to use 5W40 during those hot months.

If I lived somewhere tropical, like south florida, I would stick to a 10W even.

 

[N7turbo]

@Lazy2.5 why do you refer to it as 0W? The viscosity at those temperatures will be closer to 20 or 30 depending on the oil. It doesn't stay at "0" for more than a minute after startup.

 

[RedBaron]

These charts claim that a 0W, 5W and 10W are all suitable for well over 40c+ operation.

The first number (like the 5 in 5W-30) relates to the cold temp performance. It's the second number (30) that relates to the HIGH temp performance. Thus, in that table, they are all -30 weight, which is why the high temp bars all end at the same point. If you need protection at even higher temps, go to an xW-40 or -50.

 

[Lazy2.5]

@Lazy2.5 why do you refer to it as 0W? The viscosity at those temperatures will be closer to 20 or 30 depending on the oil.

The first number (like the 5 in 5W-30) relates to the cold temp performance. It's the second number (30) that relates to the HIGH temp performance. Thus, in that table, they are all -30 weight, which is why the high temp bars all end at the same point. If you need protection at even higher temps, go to an xW-40 or -50.

Right, I was referring to the Winter weights because I was also comparing how they theoretically perform in cold temps, based on the chart provided, though I did not differentiate this from the hot temp rating in my original post, correct.

 

[madar]

Yes, no 10W-50 in the mix in earlier days. Here’s the oil viscosity chart from Mazda CX-5 Owner’s Manual world wide back to earlier days:

View attachment 382543
View attachment 382544

It's an interesting change since it's not an energy saving weight. It seems to be out of a newer online manual. I wonder it it's in response to the rollback in CAFE standards? Good to see you back by the way.

 

[N7turbo]

It's an interesting change since it's not an energy saving weight. It seems to be out of a newer online manual. I wonder it it's in response to the rollback in CAFE standards? Good to see you back by the way.

It's the Euro manual.

 

[dunhillmc]

It's the Euro manual.

iirc, the oil change interval is 20k km (12k mi) in europe and their gas is pretty much the equivalent of premium here

 

[bojo]

Tried to get a answer from Mazda about warranty coverage if using 5w-30 in the USA. Initial response they said 0w-20 was mandated for better mileage and using another viscosity “can” lead to possible rejection of warranty.
I pushed them to answer whether if I follow the severe duty schedule, change every 5k with full syn 5w-30, whether my warranty would be invalidated. Response:

“Thank you for contacting Mazda Customer Experience Center.

Hello again, this is XXX from the Mazda Customer Experience Center.

I will include a few documents that provide more information regarding the maintenance of your vehicle. I will include a link to the full documents below as well.

You are responsible for properly operating and maintaining your Mazda Vehicle in accordance with the instructions described in your Owner’s Manual. If your vehicle is used under severe driving conditions, you should follow Schedule 2 of the maintenance requirements described in your Owner’s Manual.
? Maintenance Records - Proof of Maintenance
To continue warranty eligibility and to protect your investment, it is your responsibility to properly maintain your vehicle according to factory recommended schedules outlined in your Owner’s Manual. As part of this you must keep your maintenance records, receipts, repair orders and any other documents as evidence that maintenance was performed. You must present these documents, should any warranty coverage disagreement occur. Failure to do so can result in your warranty being voided either in whole or in part.

Only use SAE 0W-20 oil “Certified For Gasoline Engines” by the American Petroleum Institute (API). Oil with this trademark symbol conforms to the current engine and emission system protection standards and fuel economyrequirements of the International Lubricant Standardization and Approval Committee (ILSAC), comprised of U.S. and Japanese automobile manufacturers.

If you live in the United States it requires SAE OW-20 oil with the Certified for Gasoline Engines stamp by the API.

If you live in Mexico use API SM or higher, SAE 5W-30 engine oil. If SAE 5W-30 engine oil is not available, use SAE 5W-20, SAE 0W-30 or SAE 10W-30 engine oil. The quality designation SM, SN or SP must be on the label.

Please contact us back if you need further assistance. Thank you for being the best part of Mazda and have a wonderful day.”

“Requires” 0w-20’ in the US. Cross the border and magically 5w-30, 5w-20, 0w-30, 10w-30 are okay!
What bull! We have to use a thin oil due to CAFE, and they admit its for mileage, while admitting the 2.5 runs fine on most common viscosity’s. Which we all knew
So debating whether to go with this crap for 60k, which may lead to more wear, or use my preferred 5w-30 and chance warranty issues. Leaning towards saying screw it, and taking my chances. I’ve driven over a million miles and never had a engine failure, or even had a engine burn oil. I need to get 200k out of this car

I FINALLY decided to go with 5w30 on my 2025 skyactiv NA engine, a lot due to the great people here. I wonder why are they telling you it REQUIRES 0w20? That is NOT what the manual says. The manual says RECOMMENDS 0w20 for MAXIMUM FUEL ECONOMY. They need to get their wording straight. Either Recommended, or required and stick to it. At anyh rate, Im going 5w30 for the summer without hesitation. Pennzoil Ultra Platinum.

 

[ruthrj]

Like all things in life, use what best suits your application. My 2.5T gets 5w-30 as prescribed. Normal everyday driving, it’s a good viscosity, it’s what the doctor ordered.

Our RAV4 hybrid gets 0w-16. That scares a lot of folks on the RAV4 forum and they too bump up the viscosity (0w-20 despite it having the same film thickness as 0w-16, or going higher to 5w-30). However, I’m fine with 0w-16 due to repeat engine starts and stops. I want the oil to get where it needs to go as soon as possible when the engine fires back up. It’s our grocery getter, no towing, nothing crazy. Admittedly I do 5k mile changes instead of 10k because it’s cheap, but I digress. It’s a little spooky how the hybrid tends to start and stop before fluids reach normal operating temps, I don’t really want to do that with a cold thicker oil.

My Titan V8 gets 0w-30. It’s supposed to get 0w-20 per the manual but I occasionally tow about 5k pounds worth of travel trailer. I wanted a little extra insurance the 30 brings for towing vs relying on the 20. Im sure I could use 5w-30 without issue, but sticking to 0w-30 means the engine won’t experience any viscosities above or below what it would have seen during operation with 0w-20.

The 2.5NA doesn’t start and stop like my RAV4 hybrid. Never had an issue running the prescribed 0w-20 for 120k ish miles on my 2013 CX-5, but there isn’t any harm running 5w-30.

 

[Lazy2.5]

Like all things in life, use what best suits your application. My 2.5T gets 5w-30 as prescribed. Normal everyday driving, it’s a good viscosity, it’s what the doctor ordered.

Our RAV4 hybrid gets 0w-16. That scares a lot of folks on the RAV4 forum and they too bump up the viscosity (0w-20 despite it having the same film thickness as 0w-16, or going higher to 5w-30). However, I’m fine with 0w-16 due to repeat engine starts and stops. I want the oil to get where it needs to go as soon as possible when the engine fires back up. It’s our grocery getter, no towing, nothing crazy. Admittedly I do 5k mile changes instead of 10k because it’s cheap, but I digress. It’s a little spooky how the hybrid tends to start and stop before fluids reach normal operating temps, I don’t really want to do that with a cold thicker oil.

My Titan V8 gets 0w-30. It’s supposed to get 0w-20 per the manual but I occasionally tow about 5k pounds worth of travel trailer. I wanted a little extra insurance the 30 brings for towing vs relying on the 20. Im sure I could use 5w-30 without issue, but sticking to 0w-30 means the engine won’t experience any viscosities above or below what it would have seen during operation with 0w-20.

The 2.5NA doesn’t start and stop like my RAV4 hybrid. Never had an issue running the prescribed 0w-20 for 120k ish miles on my 2013 CX-5, but there isn’t any harm running 5w-30.

According to that chart, a 10W weight is good for up to -25C.

So, unless you are regularly driving in -25C weather with a 10W, this whole "cold start flow" argument is just so overbaked.

 

[N7turbo]

We like our cold flow. And the formula matters, too.

 

[ruthrj]

According to that chart, a 10W weight is good for up to -25C.

So, unless you are regularly driving in -25C weather with a 10W, this whole "cold start flow" argument is just so overbaked.

Fair enough, I haven’t seen it considered much. From what I’ve seen online, 10w takes much longer to move than a 0w even at room temp. I prefer a 0w which flows faster to where it needs to go for that initial 1500 rpm warm up (even if it’s 0 C to 20 C). 0w pours like water at room temp (which has always scared folks, I made a mess the first time I poured lol!), 5w slightly thicker (fun to pour for the 2.5T), and the 10w for my lawn mower pours a little syrupy. I think a 0w cold plus higher operating temp weight can give you the best of both worlds.

 

[Lazy2.5]

Fair enough, I haven’t seen it considered much. From what I’ve seen online, 10w takes much longer to move than a 0w even at room temp. I prefer a 0w which flows faster to where it needs to go for that initial 1500 rpm warm up (even if it’s 0 C to 20 C). 0w pours like water at room temp (which has always scared folks, I made a mess the first time I poured lol!), 5w slightly thicker (fun to pour for the 2.5T), and the 10w for my lawn mower pours a little syrupy. I think a 0w cold plus higher operating temp weight can give you the best of both worlds.

But, that chart strongly suggests there will be no issues with oil -flow, provided you are within that range. I'm sure it's also on the conservative side too.

 

[ruthrj]

But, that chart strongly suggests there will be no issues with oil -flow, provided you are within that range. I'm sure it's also on the conservative side too.

Agreed, it’s not even a suggestion. It’s in black and white that the manufacturer says it’s fine for the application presented. Pick a viscosity applicable for your use case out of your vehicle manual and I don’t foresee issues : )

We’re going to have folks in 10-15 years that are very happy our vehicles didn’t suffer an oil related failure. The two camps for the 2.5 NA will point to either the 0w-20 on the cap or the worldwide 5w-30, and there will be much rejoicing.

Wish I could even track down a reliable source for time 0w, 5w or 10w takes reach to critical engine parts. Did an AI deep dive and it’s attributing oil findings to SAE articles on flame spray characteristics. After fixing prompts to ignore forums and cite only scholarly articles, finally got some real sources but they’re from 1982 and 92 (pre 0w, no VVT, etc). It makes a pretty table but I don’t think it’s worth sharing as I cant get it to cite a source. All I can figure is considering the whole industry went 0w or 5w and we don’t have heaps of vehicles in the junkyard from oil failure, it likely wasn’t a bad move.