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- Plano, Texas, USA
0w20 or 5w20
- Thread starter prathameshsahay
- Start date
Jack Rabbit
Banned
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- 18 Mazda CX5 AW
Yep.I know most people won't agree with me but the lower oil viscosities are for the good of the CAFE numbers, not for the good of the engines. Will a 0w-20 get your engine way past your 36,000 warranty period? Absolutely. Gunna see 200,000 ?? Maybe. My brothers 2017 F150 5 liter V8 says 5w-20 on the cap. Not me. I live in a VERY cold place and every vehical I own gets 5w-30 full synthetic every 6000 miles, all 12 months. I own cars/trucks from 1986 to 2022. And they are very happy!. (Kirkland SP 5w-30 actually). And for the love of God don't use FRAM oil filters. Haha
The thing you have to remember is the engine is an expensive piece of highly tuned machinery . So why risk it? There are alot of factors that come into play including pressure and temperature. Will the thicker oils lubricate and protect the bearings and engine better. Sure will ...but only the sections it can get too. Cold weather and tight tolerances may mean no oil where needed. The thicker oils will not flow as freely through the oil pump until warm. Thus no oil during startup when needed.Add in the fact that the engine coolant cools not only the engine but also keeps the oil from super-heating. Im not a scientist but i would think thicker oils would be harder and take longer to cool off. As the mazda engines are high compression that means the engines create alot of heat. Which is bot getting dissipated as fast/easily.
It is complex and there are alot of interworking part's. So why Messi with it? Except using thicker oils on an already worn out, old engine thats ni it worth alot, why screw with the engineers design?
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- Plano, Texas, USA
On the contrary, many including me believe the low viscosity oils such as 0W-20 are only good for CAFE numbers. The added timing chain protection feature on newer GF-6 oil standard is due to the lack of it from older thinner oils.I know most people won't agree with me but the lower oil viscosities are for the good of the CAFE numbers, not for the good of the engines. Will a 0w-20 get your engine way past your 36,000 warranty period? Absolutely. Gunna see 200,000 ?? Maybe. My brothers 2017 F150 5 liter V8 says 5w-20 on the cap. Not me. I live in a VERY cold place and every vehical I own gets 5w-30 full synthetic every 6000 miles, all 12 months. I own cars/trucks from 1986 to 2022. And they are very happy!
Jack Rabbit
Banned
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- 18 Mazda CX5 AW
But you cant just take low points. We still get -10 F where we live. The question is what is the viscosity of the 5W-30 be at - 10F versus the viscosity of 0W-20 at -10 F ? At - 10F, the 0w-20 will flow more freely. And while i dont know the exact viscosities, ive seen the 5w-30 takes alot longer to pour versus 0w-20 in very cold temps
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- Plano, Texas, USA
But we’re talking about “thicker” 5W-30 oil which is recommended by Mazda for its SkyActiv-G engines used worldwide.
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- Plano, Texas, USA
As long as the oil with the said viscosity is approved by the SAE which can be used at -10°F, we shouldn’t be worried about it.
Besides, the protection is only for a very short period of time during the initial start-up in very cold temperature. For mostly very hot weather in Texas, high temperature protection is more important to the engine. Most likely 5W-30 oil protects engine better than 0W-30 in such conditions.
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Jack Rabbit
Banned
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- 18 Mazda CX5 AW
Also though, if 5w-30 raises fuel consumption thus their is more gasoline combustion, thus more heat and pressure thus more engine wear...
Now to those that trade in cars every few years, they may not care.
But I run mine til the frames rust out. Until myth-busters does a segment on engine wear, i think ill stick with the engineers specs, even after the warranty period.
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- Plano, Texas, USA
Yeah, and Mazda engineers said 5W-30 oil can also be used in our SkyActiv-G engines, period. (Again, see post #15)
Different oil formulations give different results. I was a diehard PP user for years, both on my current CX5 and my '14 model. I was using a quart of oil every 4k miles. I do a lot of hard driving. I experimented with Ravenol 0w-20 oil just to see if was an engine issue or oil. Ravenol is mostly a PAO oil (a true synthetic oil, and quite expensive being imported from Germany) for a year and was using almost a quart at 6500 miles. It's a fantastic oil and the engine was very quiet running. Now I'm using Mobile 1 EP 0w-20, which is about 30% PAO, up to 600 miles on this change and no oil consumption yet. GDI engines are tough on oil. I'm still bound to an extended warranty so I'm sticking with 0w-20 for now. I always believed 0w-20 was crap.
Yes, the push for xW-20 oils (and thinner) has been for fuel economy reasons. That doesn't mean it's bad for protection. It's complicated.
xW-30 might retain thicker films in the highest-temp, highest-shear areas of the engine. xW-20 will reduce wear before the engine gets up to temp, which is when many of us will be causing most of our engine wear. What's the net effect? None of us here has any idea one way or the other. It will vary from case to case based on variables most of us can't even comprehend let alone figure out.
Plus, if you buy an xW-20 oil that meets modern specs, there's actually more of a guarantee of high quality base stocks than if you buy an xW-30 that meets the same specs. The lower the viscosity grade, the higher the base stock quality "floor" to prevent it from cooking off too easily. Again, what's the net effect for either viscosity grade? Impossible for us to say.
You know who knows? Mazda. What's the probability they'll share what they know? Zero.
All we can say for sure is that any oil that meets the manufacturer's specs will work well enough that it probably won't be the liming factor on engine life. Isn't that what we're all trying to achieve?
xW-30 might retain thicker films in the highest-temp, highest-shear areas of the engine. xW-20 will reduce wear before the engine gets up to temp, which is when many of us will be causing most of our engine wear. What's the net effect? None of us here has any idea one way or the other. It will vary from case to case based on variables most of us can't even comprehend let alone figure out.
Plus, if you buy an xW-20 oil that meets modern specs, there's actually more of a guarantee of high quality base stocks than if you buy an xW-30 that meets the same specs. The lower the viscosity grade, the higher the base stock quality "floor" to prevent it from cooking off too easily. Again, what's the net effect for either viscosity grade? Impossible for us to say.
You know who knows? Mazda. What's the probability they'll share what they know? Zero.
All we can say for sure is that any oil that meets the manufacturer's specs will work well enough that it probably won't be the liming factor on engine life. Isn't that what we're all trying to achieve?
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- Plano, Texas, USA
Yes. And the discussion started with when the engine is consuming oil and is getting noisier, use Mazda (also) recommended 5W-30 oil on the 2.5L NA could help the situation.
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- Plano, Texas, USA
Most definitely. Different brand of oil with the same viscosity may have different result on oil consumption. When I was with VW Passat forum people swore that the hard to find made in Germany Castrol Syntec 5W-30 oil has much better “performance” and much less oil consumption for the 2.8L V6 than the made in USA Castrol Syntec 5W-30 oil which was widely available although the packages were looked the same other than the country of origin.
Toyota has been using 0W-20 for like a decade or so and have been using in my GX for years. No issues...
So far the Mazda moly 0W-20 which I have used since new has kept oil consumption to "not noticeable"
I will continue to use it in those vehicles... only auto I deviate is the '07 G35x.... still using the specified 5W-30 and no noticeable oil consumption there either.
Alway used the Mazda moly in the CX-5 and Amsoil in the other rigs.
So far the Mazda moly 0W-20 which I have used since new has kept oil consumption to "not noticeable"
I will continue to use it in those vehicles... only auto I deviate is the '07 G35x.... still using the specified 5W-30 and no noticeable oil consumption there either.
Alway used the Mazda moly in the CX-5 and Amsoil in the other rigs.
So where is Mobil1 Extended on this for 5-20? I know years ago I read that the Mobil1 Extedened were true full synthetics, does this apply to the 5-20? I live in South Florida and will not ever drive in super cold climates so I figure I would try out 5-20 cause startsup tend to be a tad noisy and well 5 weight is what is recommended in Mexico - a closer climate match. I did not got with 30 cause well the engine temp is the same here as everywhere in the US. Startup is where the climate actually makes a difference on the cold weight. Please correct me if I am wrong or let me know if the Mobil1 extedended is not true full syn.
Thanks
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- 2019 CX-5 AWD
I wouldn't even bother with 5W-20. I switched from 0W-20 to 5W-30 several oil changes ago in 2022 and much, much prefer it. I don't care about the startup noise (though there is a pronounced difference), I do care about the noise while actually driving. There is about a 1 mpg difference, from 24 to 23, but WELL worth it for the quieter, more luxury car like driving experience. Switched to 5W-30 from 0W-20
Thanks to you as well. I appreciate those questions because they show where I might have been unclear.
I'm not saying all 5W-20 is a blend and all 0W-20 is synthetic. I'm saying, if you took the absolute worst 5W-20 and 0W-20 oils you could find (that still met modern OEM/industry specs), the 0W-20 would still meet the definition of "fully synthetic" whereas the 5W-20 might not. This is only an issue if you're shopping on price or just picking up whatever's on the shelf without paying much attention – which I know a lot of people do. In that case, it's best to stick with 0W-20 because at least that way the odds of getting a full synthetic are 100% (as long as you're sticking to big name brands).
No need to worry about this with a product like Mobil 1 EP. All grades of Mobil 1 are fully synthetic, including the EP line. There might be differences in base oil quality between the grades, but nothing worth worrying about. So, if you're looking at that product line, pick your grade and rest easy.
As for the W number (it stands for "winter", not "weight"): Yes, you're probably right that 5W-20 is fine for your purposes. Can't say whether it'll reduce your startup noise; the relationship between noise and viscosity isn't always what we think it should be. And 0W vs 5W is about what happens at VERY cold temps – much colder than you'll see in Florida – so it's not necessarily true that the 5W-20 will be any thicker during your cold starts. But either way, your engine will be fine with it. It'd probably also be fine with any xW-30 that meets the relevant API/ILSAC specs, too.
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