Goldy, this is pretty factual info, and not hearsay or internet old-wives tales. I think you should find the info pretty easily.
The 30 vs 20 is the operating temperature viscosity. It's not just more protective additives. So higher viscosity at operating temp will reduce mpg slightly.
The big manufacturer push to 20 oils was driven primarily to help increase their EPA MPGs, (benefit #1, it wasn't a secondary benefit).

 

Hmmm... Maybe you could point me to some of that factual information.

I'm always ready to learn new stuff!!!

 

QUICK MODERATOR NOTE: This thread originally was part of https://www.fitfreak.net/forums/2nd-...ml#post1078267

put in "5w20" and "cafe standards" into google and you'll get a lot of hits, although I admit they will be dumbed down simplified articles or ones written trying to sell you amsoil or other oil-related products or other agenda rather then scientific studies.

Notice you won't find any disagreement about the reason for the switch. The disagreement is usually along the lines of is this fuel savings is worth potential extra "wear" and whether new engines and new oil improvements already takes that that into account and so won't cause wear. Then usually this spirals out of control into semantics of how much extra wear and how either the rest of your car will will fall apart before the extra wear makes a difference or Judgement Day happens and the robots take over anyway.

I think if you probably dig into some of those forum threads, then you'll eventually find someone who will link to scientific studies if you want more unbiased presentation of the info.

 

I love oil threads, I don't feel like wasting anymore effort on them, but I will link this as food for thought:
https://www.fitfreak.net/forums/othe...-friction.html

 

I thought maybe you had some real information as you wrote like you actually knew there would be a difference.

I know why manufacturers choose the viscosity ratings they recommend for their engines. I just don't think there is a single manufacturer that has chosen an oil for mileage reasons.

If you have information showing otherwise I'd love to read it!

 

Don't be a lame new member.
I'm not going to dig stuff up to prove to you to win an internet oil argument. If you truly are curious to learn, google the terms i gave you and go through the first 100 links and forum threads that come up, and follow all the links within those links.

If you want to win an internet argument, you win.

If you want oil heads to find the data for you, post on BITOG and then they pull the data for you, or they may also completely ignore you for not doing your own searching.

::repeat to myself, this is an oil thread, this is an oil thread.

 

If K were Pi, I think the equation's designer would have stated this. K is some constant derived from Pi plus whatever is needed to form a meaningful plot given the units for force, viscosity, and diameter.

gigo.

 

Take a deep breath. At least octane hasn't entered the discussion...

1-2% seem to be the efficiency gains of dropping from 5w30 to 5w20. Somewhat more going to 0w20. The Honda Insight was the first car to specify 0w20 for its efficiency gains, even though it wasn't an economical choice back in the day. source (see section 2.2 paragraph 2)

 

yea, taking that breath now, but new member with 11posts
pulls out
"i thought you had some real information" and continues with their own similar gut assertions without even doing a speck of research, just sounds like trolling for an argument rather then genuinely being curious and grateful for the time spent to write up how to get an answer to his question.
I'm in this forum to help and have fun, not to win arguments (although others do enjoy debating).

Thanks for providing the link. Do note that it's 11years old, and the general findings holds true today, but the market may have moved since then.

 

Dropping the lower viscosity number will reduce friction while an engine is cold, so I would believe going form a 5W to a 0W could give a slight efficiency advantage. That advantage would fall sharply for a vehicle driven in very hot climates and running long trips.

Nope, I'm not getting into an oil thread war, just pointing out that information found on the internet is often misquoted, misinterpreted and misunderstood.

Reading your source above I found the claim of 1%-2% gains came from a paper written over 12 years ago by S. Tseregounis and M. McMillan, titled: "Fuel Economy Gains with Modern Technology, SAE 5W-20 Engine Oils in a GM Engine as Measured in the EPA FTP Test"

Now if you read that paper the authors are testing a 5W-20 GF3 quality oil against a 5W-30 GF2 quality oil.
Why even the references in your quoted article state that much.

So what we have is a test using the 'old' oil technology and comparing it to the 'new' oil technology, with a very different additive package in each.

Further in reference 4 you will find that the same GF2 oils treated with detergents and friction modifiers (a new 'package') resulted in a 1% to 4.7% gain in fuel efficiency.

So is it the viscosity difference in the hot oil or is it the very different additive package that creates the increase in fuel efficiency? I don't know, but I didn't make the blanket statement either.

Will Mobil 1 5W-30 give you 1% - 2% less mileage than WalMart 5W-20?
I don't think so but that's what some people want us to believe.

I'm just asking for a little back-up documentation before I accept anything as fact.

 

I'm sorry I didn't realize to be respected one needed a higher post count.

I'm just asking for some back-up to a claim I think is suspect.

 

The point of the high post count, is that you may not have been here or elsewhere awhile to go through the previous threads or discussions that may have covered your topic. maybe you're completly new to cars completely. So high post count and time here does count for something.

So someone fresh shouldn't come in and then start throwing around trash like
"I thought maybe you had some real information as you wrote like you actually knew there would be a difference."
or basically just throwing back what someone else wrote to try to help you right in their face and backhandedly insulting their knowledge is just straight bad manners.

This is a membership forum, not anonymous commenting, there should be some sense of community here.

Your technical post is actually quite logically sound and adds to the discussion, without the unneeded insults, but I will ask you to find a source that backs up what you claim, and please post that for review then we can tear that apart for inconsistencies too.

 

I'm not claiming anything! I don't think your mileage will drop going from 5W-20 to 5W-30, that's all.

 

This is not necessarily directed at you, and maybe this is more of a philosophical soapbox.

What happens a lot in these discussions, when it becomes incredibly hard to prove something. There will be some inconsistency or factor in a test which someone will claim invalidates the study.

The purpose of finding a counter claim is to establish is there someone out there that believes the same thing you do? Especially for an old topic as a 12year old study.

Then the philosophical question is: If the entire community including a series of experts in the field believes something, sure maybe you take the stand that you don't take it for granted, and need it to be proven to your standards.
But really if nobody else saw the flaw, does this mean that you somehow are smarter then everyone else? Somehow you found the loophole that nobody else saw?

Are you really the Gallileo, or Newton, or Columbus who got it right and everyone else got it wrong?

Then, is there even a field in these modern times where someone off the street with just self-taught knowledge can have the more correct answer than industry folks who spent years studying and years researching in the field? Do all fields require the deep knowledge to move forward, or can shallow knowledge prevail in places?
I personally believe that right now, new knowledge is built on the shoulders of those out there already, and you need that deep knowledge.
For something like this, where it's a big industry with a society of engineers and a national lab who researched it, I believe this even more so, and to some degree trust they got it right over my own shallow knowledge. (If this was some podunk open source new software, I could see that maybe I'm the first one to spot a problem)

Take for example, the controversy of whether a dirty air filter affects MPG done by the national labs in 1970s. As the years ticked over, you could find plenty of the knowledge continuum that cried outdated and demanded a retest with an EFI engine; which was eventually completed and validated that claim. So yes, there was a wrong twist there, but there were people in the industry who saw it and cried out immediately.

If you don't see anyone in the community of experts crying foul over this claim, not a single one, maybe that in itself is worth something as proof.

 

You're right. Annoying, but right.

The SAE may have better, more current research, but their database is pay per view. Other than that all I find is anecdotal.

This might be interesting, but not $23 interesting.

From the abstract: The results show that reducing engine oil viscosity is effective for improving fuel efficiency.

 

I'm not going to argue this, I just wanted to know if what was being said was backed by facts or is just some fantasy. I'm very eager to learn new things, but I don't blindly follow anybody. I DON'T see the group of experts agreeing that a modern 5W-20 oil is getting better mileage than a 5W-30 oil in normal vehicle use. That's my point.

The proof that was offered is an old study comparing two completely different oils, with two completely different additive packages, using engines that are unbelievably different than the ones we have today.

To take that and make a blanket statement that if someone runs 5W-30 in their new Honda Fit they will get worse mileage is misleading and from what has been shown, completely unsubstantiated.

If anyone wants to believe it, fine! Everyone can believe whatever they want. Just so we all realize the facts leading to the conclusion are really fuzzy.....

 

It's not a study, but:
Why Have Some Car Makers Moved from Recommending 5W-30 to 5W-20 or 0W-20 Motor Oil?

 

Going to a 0W from a 5W anything is a move to a thinner oil. That will reduce friction at start up. No argument there. How that could effect mileage is debatable, but at least it makes sense. Engines designed to run on 0W oils are designed with closer tolerances than those that run on 5W or 10W.

 

Ah Grasshoppers HMMMMMMMMM UMMMMMMMM. You are assuming that the mechanic put in 30W oil Maybe the service writer, put 30W on the receipt accidentally. Maybe the computer Gremlins transposed a 2 to a three, billions of calculations every second, fertile ground for Gremlins. Could the mechanic or parts dept affect what shows on the bill?

To be certain an oil sample must be examined.

Instead of replacing the filter did the mechanic clean the old filter and leave it? tossing the new filter in his locker?

I am a voyeur, I like to watch dirty things, like oil changes JIm 0311

 

I wondered that back in post 8.... Did they just write 5W-30 on the receipt but actually use 5W-20?

I'm sure if you ask they will say they used the proper oil....