Honda Odyssey Forum banner

5w-20 Vs. 5w-30

59K views 82 replies 30 participants last post by  0dyfamily  
#1 ·
I have not been able to find any 5w-20 oil in stock in my area (in Mobil 1), but can find 5W-30. Interested in opinions regarding using the -30.

Brian
 
#2 ·
Welcome Neighbor!

I get our oil changed at the local dealer, and they use Castrol Syn-Blend 5-20. Lots of oil threads here, so do a search.
 
#4 ·
There are many opinions. From what I have read, there does not seem to be much difference running 5-30. I have also read M1 5-30 is on the thin side anyway, so it's probably close to a 20 wieght. There should be no problem running it.

I've decided to use M1 5-20 though, since I can easily get it and I just want to insure Honda can't come back on my warranty and say "you didn't use the right oil viscosity."

BTW have you looked at Wal-Mart? All of them by me carry M1 5-20. Out of stock sometimes though.
 
#5 · (Edited)
#8 ·
Should there be an oil related engine problem (I know, it never happens to a Honda), do you think one could win the ensuing argument, if one had not followed the manual? I would not want to go there, even though the 5w-30 would not be the cause, being put in the position of proving it would be more than I would want to endure.

Jerry O.
 
#9 ·
We have an early 2001 manufacured in 2000. The owners manual says 5w20 and the viscosty chart that you usually find in the manual is blank. However, the oil filler cap says 5w30. So if Honda can't be bothered to match the filler cap data with the owners manual, it must mean either 5w20 or 5w30 oil is fine.
I run Mobil 1 5w30. Probably switching to Amsoil though.
 
#10 ·
If you spend a bunch of time on Odyclub searching the forums you will find this:

(1) This engine uses 5W-30 everywhere in the world except the US.

(2) This engine used 5W-30 in the US until the CAFE regulations changed to say that if you were going to submit an engine with 5W-20 in it for fuel efficiency tests, you had to make your customers run that oil.

(3) I believe there are Ody's out there that have stickers over the 5W-30 badging to say 5W-20 after that regulation went into effect.

Thus, I run 5W-30 in my van as it is more available, and I believe it is what this engine was designed to run. Furthermore, I drive this van through the desert every day, and in the summer this means 110+ degree weather. The extra protection of the 30 weight is advantageous to me.

Joel
 
#11 ·
Joel, do you really think the ambient temperature of 110 means anything significant to the engine compared to, say, 80 degrees? I don't think anyone will kill an Odyssey to run 5-30. Although, I think the SM rated 5-20 is better, partly because it is thinner, partly because there is less difference in viscosity: therefore fewer viscosity improvers are added to the 5-20...after all, viscosity improvers aren't lubricants, AND VI's break down. When all is said and done, thinner means more flow....more flow means more cooling.

I'll bet an engine run on SM rated 5-20 will actually show less wear in 200,000 miles than one run on 5-30. I know it ain't what Daddy preached, and it ain't what many relatively non-scientifically inclined mechanics preached, but, it's what the engineers observe. All this changes in heavy load and extremely high heat circumstances...such as racing. High heat such as 110 degrees means very little, if anything to an engine. It can overwhelm a malfunctioning cooling system, but, a hot cylinder head isn't significantly affected by ambient temps.
 
#12 ·
Titan said:
I'll bet an engine run on SM rated 5-20 will actually show less wear in 200,000 miles than one run on 5-30. I know it ain't what Daddy preached, and it ain't what many relatively non-scientifically inclined mechanics preached, but, it's what the engineers observe.
So far, only Honda, DC and Ford recommand 5W-20.

Are you implying Toyota, GM and other automaker engineers don't see the benefit of 5W-20?
 
#13 ·
lelandstanford said:
So far, only Honda, DC and Ford recommand 5W-20.

Are you implying Toyota, GM and other automaker engineers don't see the benefit of 5W-20?
Not at all. However, it took over a decade for people to accept 5-30 when it first came out. Same reluctance for people to switch as now.

When the engine engineers begin cramming more stuff in smaller spaces, and therefore perhaps designing the engine with tighter oilway lumens, it may require a thinner oil to flow sufficiently to adequately cool parts.

If you can take a Ferrari engine and run it on 10 or 20 weight oil when driving around town in Miami...like a fellow named Dr. Haas does, but, the same engine requires as high as a 60 weight when racing due to 300+ degree oil temps in order to keep the oil pressure at a given value at a given rpm, you can see the requirements aren't as simple as 5-20 vs. 5-30.

A very simple way to determine correct oil viscosity is by achieving the engineer's required pressure value at a given rpm. As long as an oil delivers the correct pressure at operating temp at a given rpm, it is thick enough...furthermore, the thinnest oil which will meet these values is the best because it provides more flow. More flow equals more cooling.

One good thing about 5-30's is that it shears to 20 weight fairly soon anyway...unless you're talking about some synthetics.

Watch GM and Toyota. They'll be recommending 5-20 soon.
 
#14 ·
Titan said:
Not at all. However, it took over a decade for people to accept 5-30 when it first came out. Same reluctance for people to switch as now.
I was refering to auto engineers not general public/consumers (if that's your definition of "people").

If Honda engineers see the benefit of 5W-20 over 5W-30 why 5W-20 was not recommanded in JDM?

Generally speaking, Japanese automakers tend to try "new things" in Japan before other markets.
 
#15 · (Edited)
lelandstanford said:


If Honda engineers see the benefit of 5W-20 over 5W-30 why 5W-20 was not recommanded in JDM?

Generally speaking, Japanese automakers tend to try "new things" in Japan before other markets.
My impression of the Japanese culture is that history is respected much more than in the USA. Therefore, if the history consisted of using a heavier oil, it will be harder to convince the Japanese people to go to thinner oils than it is in the USA...and we've been VERY slow to even adopt the 5-30 standards that the pesky Automakers were trying to force us to use starting about 15 years ago! 10-30 and 10-40 is still VERY COMMON at Walmart...there's a reason...and it has nothing to do with being well-educated about lubrication of automobile engines.

Also, I don't know if it is generally true that Japanese automakers try new things in Japan first....it seems they come to the US pretty much with the bugs worked out.

A 5w-XX oil is a 5 weight oil with viscosity improvers added to it in sufficient quantities in order to make the oil "act" thicker at higher temperatures. To get a 5w-10 oil, they don't have to add much VI. To get a 5w-20, they add more VI. To get a 5w-30, they add even more VI. VI's are long chain molecules that make the oil "act" thicker. These long chain molecules are broken into smaller molecules in an engine environment, and THEN the oil acts more like it's base oil...i.e., it acts thinner over time. Those people that do oil analysis on their vehicles often report BETTER wear numbers on oil that has been used for a couple of thousand miles....it has been suspected that one reason may be the oil was too thick for a while, and the engine is being better protected by the thinner oil (even though it has a bunch of broken down VI's...and remember VI's aren't lubricants). Real surprise to many people.

Like I said, it doesn't really matter much if you choose to use a 5-30 instead of a 5-20, because within a couple of thousand miles, the 5-30 will have it's viscosity improvers broken down enough to qualify it is as a 5-20 anyway. Since SM rated 5-20's don't add as much viscosity improver, they stay in grade much better....the 5-20's also lubricate better because of less viscosity improvers that are added to it in the first place....since VI's aren't lubricants.

Do I think you can get over 200,000 miles if you ran 5-30 in this Honda engine? Of course. Do I think you'll have less wear than if you had run 5-20? No....5-20 is a BETTER lubricant for this engine....due to scientifically proven characteristics of lubrication needs of passenger cars. In the meantime, you get better fuel economy also.

BTW, Ford Back-Spec'd many of their engines to the 5-20 weights. Is there any CAFE reasoning behind that? Aren't those engines "off the books" as far as the CAFE standards for new fleets go? I think maybe Ford realizes the better lubrication qualities of the new SM rated 5-20's and just want their customers to be satisfied with the Ford product so they'll be more likely to buy Ford again.

Run what you want, you can probably run a 5-40 and still get over 200,000 miles on the engine. I'm running 5-20 because of the science behind it.
 
#16 ·
I'm very puzzled by your assertion that a 5W30 oil is a 5 weight oil with thickeners added. I am not an oil engineer, but the motor oil bible disagrees with you.

"the two numbers really have little to do with each other. the final number based upon the kinematic viscosity at 100 degress C, as we discussed for monograde oils. So, if a multi-grade oil, when heated to 100 degrees C, falls within a certain kinematic viscosity it is classified as a certain SAE grade (the last number - like the "30" in 5W30).

further down

The first number (the "5" in 5w30) is only a relative number which basically indicates how easily it will allow an engine to "turn over" at low temperatures. It is NOT a viscosity reference. In other words, a 10w30 is NOT a 10 weight oil in cold temperatures and a 30 weight oil in warm temperatures"

Joel
 
#17 ·
Joel, I'd have to defer to the experts. My basic understanding is that a petroleum based multigrade oil is an oil that is "about" the viscosity of the first number, with enough Viscosity Index Improvers (long-chain molecules) added to make it act thicker at operating temperatures. As the oil is exposed to operating conditions, the long-chain molecules begin to be broken, and the oil slowly "loses grade", or, gets thinner...more like it's base oil...which is close to the first number. This has recently been tweaked a bit further, because esters can be used instead of the viscosity index improvers, in order to achieve a similar effect.

Synthetics are different, as least to my basic level of understanding: synthetic lubricants are more like the second number of a multigrade oil at operating temperatures, but, the inherent characteristics of a synthetic can have it acting like the first number at sub-operating temps....no viscosity index manipulation molecules added. So, there is less degradation, or falling out of grade, with synthetics as the oil ages in the engine.

Then, with the newer SM rated oils (like the recent 5-20's), the lines of petroleum and synthetic are being blurred...so, it gets more complicated.

I'll re-iterate, this is MY basic understanding. It isn't uncommon for simplification to be inaccurate to some degree. I'd love to know the more correct basic view, should my view be faulty.
 
#18 ·
Well, since our basic understandings are very different, I'm going to point you to my source. If anyone knows any reason why this book isn't authoritative, I'd love to hear it.

http://themotoroilsite.com/forums/

The download link as right at the top. The book is very fascinating, and gives you a ton of good information on motor oils, how they work, what to look for etc. They don't actually recommend any specific oil, which adds a significant level of credibility to me...

Joel
 
#19 ·
Joel, interesting reading. Thanks for the link.

However, what he states and what I stated aren't far apart. This fellow stated that a multiviscosity petroleum oil is indeed made up of a basestock that isn't of the viscosity rating of either the lower or higher number. He gave the example of a 5W-30 basestock being perhaps about a 20 weight, with viscosity index improvers added to make it act like a 30 weight when at operating temperature....same basic thing I stated. (Centistokes and centipoise are terms used to describe these flow characteristics, but, not needed for basic understanding.) And, as I stated, these viscosity index improvers "shear", and the oil begins to degrade to it's normal weight...in this case, a 20-weight (for a reminder, I was calling it a basestock of 5 weight, and this used to be "more true" than in more modern times, for the following reason: Pour Point depressants).

Pour point depressants...essentially molecules that interact with the waxes normally found in petroleum basestocks, so that when these oils are cooled, the wax crystals "absorb" (his words) the pour point depressants, preventing them from forming as much as usual, which allows the oil to flow at temperatures colder than they normally would flow. This is what allows the basestock 20 weight oil to flow like a 5 weight.

So, to get a 5w30, we have a 20 weight oil with pour point depressants added to allow it to flow more like a 5 weight at cold temperatures, and viscosity index improvers to allow it to act more like a 30 weight at operating temperatures.

He goes on to state the thinnest oil at operating temperature that gets the job done is the best, because, as I said, FLOW rate of the oil is what keeps the parts cooled sufficiently.

Also, true synthetic (not just severely hydrocracked petroleum) can do without viscosity index improvers and pour point depressants...because it's basestock can simply have those flow and viscosity characteristics due to the molecules that make up that basestock. This "leaves room" (not a good term, but adequate for our discussion) for other additives...such as detergents, etc. Remember we don't want to add too much to an oil, because the additives tend not to be lubricants.

What does all this mean to the engine owner? Synthetics are better...well, they CAN be better...depends on the final product blend. Petroleum oils with tighter numbers, i.e., 5w20 compared to 5w-30, have less viscosity index improvers and/or pour point depressants added to them, so they are more likely to stay in grade longer.

He also mentioned, as I did, that with the newer refining techniques, the line between petroleum basestock and synthetic basestock is blurring. However, the polyolesters (I believe this is correct, I'm not going to go back and look right this second) are significantly different from petroleum basestock, even when compared to the "semisynthetic" severely hydrocracked petroleum products.

Are we still far apart in our basic understanding? Did I leave something out or twist something signficantly enough to be wrong for basic understanding? I'm serious...I'm not saying I have to have it correct at this point...I'm very open to correction and further information about it.

:)
 
#20 ·
No, in reading your post I think we mostly agree. If you compare your expanded post to your first, you'll see how I could get a quite different impression. You implied in your first post that 5W30 is really a 5 weight oil that has additives to make it 30 weight. Your most recent post says the opposite, that it's a 30 (or in your post 20) weight oil that has pour point depressants to allow it to act like a 5 weight at startup. See the difference?

In short, I think we agree. I only use synthetics. In my case I use Mobil 1 Extended Performance 15,000 full synthetic in my ody because it's the best oil generally available.

Interestingly, I looked on AMSOIL's site and they showed Mobil 1 5W30 offering significantly better protection than Mobil 1 5W20 (of course they show Amsoil as the best, but I found that interesting for the purposes of this discussion).

Joel
 
#21 ·
Joel wrote: You implied in your first post that 5W30 is really a 5 weight oil that has additives to make it 30 weight. Your most recent post says the opposite, that it's a 30 (or in your post 20) weight oil that has pour point depressants to allow it to act like a 5 weight at startup.


Well, I didn't just imply a 5w30 was a 5 weight basestock, I said it was....which, with more modern oils, is incorrect. And yep, I didn't say anything about Pour Point Depressant's in the first post. I used 20 weight basestock in the second since that's what the fellow in your link said. Apparently (maybe obviously?), petroleum basestocks use both ppd's and Viscosity Index Improver's to make a "tweener" basestock have different characteristics than the weight of the basestock itself.

I'm a fan of synthetics also...except for those people that drive very little, and for very short trips. I think those people might be better served to do their (once a year at 3000 miles) oil changes with much cheaper petroleum products so they can get rid of the unburnt fuel contamination, etc., that impairs the oil's ability to protect.

Thanks again for the link and the discussion!
 
#22 ·
By the way, I need to make a correction. The AMSOIL chart I was referencing shows "four ball" results for five different oils, and the Mobil 1 SuperSyn 5W30 came in second to only the AMSOIL. The one that was the worst in the chart was Mobil 1 0w30, not 5w20 as I stated earlier.

Also the Mobil1 SuperSyn is not the same as the extended performance, which is a newer oil from Mobil1 (and likely scores better than the SuperSyn).

Joel
 
#23 ·
FWIW I have been using Mobil 1 5w30 in my 2002 Odyssey and 2004 Accord. Both call for 5w20. I did a lot of research on the topic and made my decision based on the information I have been able to gather. I am fine with 5w20 but I feel that 5w30 will work just as well and have no negative effect on my vehicles (I hope to hold both to 150K miles). My Odyssey has about 62K miles already and the engine is doing fine.

You are going to get a lot of opinions on this topic so my advice is to do some research and make the decision you are comfortable with. There is a great site (bob is the oil guy, do a search) where they beat this topic to death.

I am very comfortable putting Mobil 1 5w30 in my $50K worth of cars and changing the oil/filter every 6500-7500 miles. I also use either Honda OEM (Filtech), Napa Gold or Purolator Pure One filter.

Good luck
 
#24 ·
After all this discussion, it is interesting to note that the owner's manual "recommends" 5w-20. If there were any chance of the 5w-30 being detrimental to the machinery, I would think Honda would "demand" 5w-20.

Jerry O.
 
#25 ·
Cardinal492 said:
[B I am fine with 5w20 but I feel that 5w30 will work just as well and have no negative effect on my vehicles (I hope to hold both to 150K miles).

I am very comfortable putting Mobil 1 5w30 in my $50K worth of cars and changing the oil/filter every 6500-7500 miles. I also use either Honda OEM (Filtech), Napa Gold or Purolator Pure One filter.

Good luck [/B]
If you are only going to put 150K miles on this engine, my opinion is that you are absolutely fine doing what you are doing....you aren't going to have an oil-related failure. For the absolute BEST long-term performance, you would probably be better with synthetic 5-20 for the duration of the engine's life...unless it begins to consume too much...THEN move to a 5-30. I've just heard too many accounts of engines running 5-20 for more than a quarter million miles, even pulling light trailers, and still not consuming oil (although these are mostly Ford engine reports).

The "thicker is better" mantra just isn't true....what is more truthful is, "the thinnest oil your engine won't burn off" (unless you are into heavy towing). Still, you aren't going to kill this engine running a 5-30.