0w-30 safe in an engine spec'd for 5w-20?

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So bearing clearances and oil feed orifices for lifters and chain tensioners will not be effected at all by moving up to a higher viscosity?


What I said was that there's no 20 or 30 grade that starts at a 20 or 30 grade at any ambient temp that humans can survive under. That means that if you're using a multivisc oil that is either a 20 grade or 30 grade ..it's WAY over visc at startup ....and both will transition through VERY high viscosity states before reaching operating visc. The 30 grade will start thicker ..but that's just ambient temperature semantics (Canada vs. south Tex.) So if a 30 grade causes you any "fear factor" where a 20 grade is spec'd ..you should dread starting the engine.
 
Ok, I understand where you are coming from. If flow restriction were an issue due to oil thickness, then my engine would implode with the first start up. Yes, the oil thins less as it heats up with a 5W-30 as opposed to a 5W-20. If I am thinking correctly, those two weights should be near the same thickness on a 65 degree morning. If my "clearances" can properly circulate the oil at start up, then flow rate when up to temp would be a non issue.
 
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If I am thinking correctly, those two weights should be near the same thickness on a 65 degree morning. If my "clearances" can properly circulate the oil at start up, then flow rate when up to temp would be a non issue.


Well, not the same ..but the 5w-30 @ 65F will be the same as a 5w-20 @ 50F (my visc calc is down - so I'm pulling this out of my behind) ..and the 5w-20 @ 180F will be the same as the 5w-30 @ 212F

It's like the bell curve on intelligence quotients (sorta). While some group typically contours the same curve ..15points lower ..the VAST "likeness" is ignored.
 
Q

Understand.

Without getting a piece of paper and going back to 1990, that would be 18 cars that ranged from 1.5L DOHC 4 CYL, V6 OHC, V6 push-rod, V8 push-rod, Kio Rio to Corvette. That also includes 11 owner/users. Just me, my wife, two daughters and son in laws account for 1,000,000 miles.

There may be a difference in gas mileage between a 15W-50 and a 5W-20 under lab conditions. No one has ever been able to show me a real world difference. Even if there were a difference that could be demonstrated, I would opt for the extra protection and engine life of the 15W-50.

If one is going to run/keep a vehicle only for the duration of the warranty, it would be wise to use the oil recommended. If you are looking for an absolute minimum of 250,000, that is a different story.

I also change my auto transmission fluid and filter at 12,000 miles. Change the differential oil on rear wheel drive vehicles at 12,000 miles, fuel and air filters at around 10,000. Sometimes I change the air filter when I change the oil.

I don't bowl, I don't golf, I don't chew, and I don't smoke. I fly fish and camp, a lot, and change engine oil.
 
Can and do oils work fine in non-optimal conditions, yes ...but the whole point of what we do is *to* optimize our oil selections. I guess that means 0w-20 in winter and 10w-30 in summer, lol.
 
Originally Posted By: FrankN4
I also change my auto transmission fluid and filter at 12,000 miles.


Just curious. Do you change your ATF at 12,000 miles even if the ATF is still red, and not brown?

Also, since you're also changing your ATF filter every 12,000 miles, I guess that must mean you're removing the ATF pan each time. Do you have a pan with easy-to-reach bolts? 5 of my 18 bolts are really difficult to reach, almost impossible. How often do you change the ATF pan's gasket? Does your ATF pan not have a convenient drain hole?

One last q: Does your manual call for ATF and filter changes every 12,000 miles?
 
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Thanks for the replies and discussion. I feel a little more confident about using a 0w-30 in my Honda now. I didn't mention the brand of oil because I really wanted opinions based on the differing operating temp viscosities rather than which 0w-30 is closest to a 0w-20, etc. I've actually got M1 0w-30 in the sump right now. OLM is at 80%, so I'll run it out to 5% after all. drivewaytech asked a lot of the questions I wish I'd asked in my original post.

The climate here in the desert isn't too harsh. A few weeks below freezing during the winter and summer highs in the mid to upper 90's with an occasional 100+ day. Sand storms in the spring really test your air filter, though. I'm a hopeless short-tripper, so I'm hoping 0w-XX will help an engine that's almost always in the process of warming up.

Originally Posted By: FrankN4
When the exact same engine calls for a 5W-20, 5W/10W-30, 0W-40 depending upon where it is sold, I get suspicious.

That's what made me wonder whether 5w-20 was the only acceptable grade for my car. But I didn't consider the possibility that oils elsewhere might be of different quality than those sold in the U.S.A. or that the R18A1 might be manufactured with different clearances in different markets.

Originally Posted By: Jim 5
Here's a helpful comparison for you to consider. This is 3 side by side UOA's on my wife's acura 3.2 TL which is spec'd for 5w-20....

That is a really helpful post. I actually don't mistrust 0w-20, but 0w-30 is cheaper and more convenient (5 qt. jugs). Like Audi Junkie I also have a small stash of SM M1 0w-30 I'd like to use up. Even better if it protects as well or better than the 0w-20 flavor.

Originally Posted By: addyguy
Honda is pretty picky about using what they say....you MAY have warranty troubles if you use a 30-weight....

You aren't kidding. I'm not even sure they'll allow a 0w-20 in their non-hybrids. Funny, I could have sworn a pregnant woman in the parts department at my dealership was going to assault me because I referred to a 15400-PLM-A02 as a Honeywell oil filter rather than a Honda oil filter. I almost bought the filter just to walk out of there alive.

Originally Posted By: Pablo & Gary Allan
[censored]....

Cheers to both of you. I've come to enjoy reading your posts, even though I sometimes end up learning from them.
 
In a short trip situation, technically a 0w-20 would work and "protect" better than a 0w-30. I'm in a similar boat, I'd like to use 20 weight but already have the 0w-30. The difference being I take all long trips, so I guess I am ok. The move in visc is actually quite small, so no sweat. In a nutshell, 0w-30 is the best "substitute" visc for 20 weight engines.
 
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I'm a hopeless short-tripper, so I'm hoping 0w-XX will help an engine that's almost always in the process of warming up.


In this case, then you should switch to the lighter 20 grade as inventory allows. You may also consider a conventional if the economics of it neutralizes the advantages of a snyth (which in short trip use, outside of EXTREME cold, it sorta does).
 
Short trip driving is a mixed bag. True,the 20 weight will get to its operating viscocity quicker, but you also have fuel dilution when the engine is cold. I think your doing the right thing with the 0W-30 and it should be a great year round oil for you. The extra viscocity will protect you during fuel dilution excursions.

If you look at the VOAs here, there is a Honda 5W-20 VOA that shows a 30 weight viscocity. I agree with others that there is no harm using it. I used it in my 02 Accord V6 and would recommed that all V6's use a 30 weight because of excessive fuel dilution. I have seen some really nasty UOAs on the V6 and 20 weights. The 4 cyl is not so much an issue.
 
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Thanks for the additional comments. I haven't done a UOA yet, so I have no idea if my engine dumps a lot of fuel in the oil... but at least it smells like oil rather than gas when I dump it.

Gary: Short trips are what originally interested me in a 0w-XX motor oil. If a 0/5w-20 provides more protection in this scenario, then that's what I should probably be using.
 
It won't offer any more "protection" ..per se~, but you'll get a head start on whatever terminal viscosity the engine will see at shut down. Whatever parasitic loses you see, you'll see less of them. Whatever energy you waste due to them, you'll expend less of it.

While fuel dilution is something to consider, as Tones points out, since you're never letting it get to operating temp (or rarely so) it can't really impact anything from a viscosity standpoint. Higher fuel content has been shown to aggravate some wear markers ..but if you're producing it as a routine part of your operational variable (fixed variable
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), there's not much to be done about it.
 
Try not to laugh, but I went and dumped the 0w-30 at 2:00 A.M. this morning and replaced it with 0w-20. I admit the car feels a little more responsive.

I'll try to unload the 0w-30 on one of my brothers who drives a 2002 Tacoma 3.4L. I'll use up the 0/5w-20 in my stash myself.
 
Built_Well

There was a time when I was putting around 70,000 miles a year on a vehicle(Ft Lauderdale, Fla to Dayton, Ohio sometimes twice a month). Rarely did I keep a vehicle more than 3 years. For the past 30 years it has been about 34,000 miles a year divided between two vehicles. Three years ago I decided to retire and go back for some more education(again)and I am 63 years old. I got an appointment in NE Tennessee, lots of hills and mountains. Now I live in Southeast, KY, lots of hills. I am going to have about 12,000-16,000 miles a year divided by 3 vehicles. I will change transmission fluid and filter, rear end oil, at no more than 12,000 miles because I just can't rest with the idea of a fluid sitting in a transmission or differential for two years or more.

The old Toyota called for 25,000 mile intervals, as I remember, on the 4 speed manual transmission and differential. The Chevrolet called for 50,000 transmission fluid change and "more often in severe conditions." The Silverado has maint I, normal, and maint II, severe. If you look up severe, it pretty much means if the engine is running. It will probably take 5 years, or more, to put 50,000 on the Silverado and I am not going to leave fluid in the transmission or differential for five years, not for two.

The transmission pan on the Chevrolet Cavalier is easy to get to and I remove the bolts with a rechargeable wrench.(Black and Decker) I put a pan for roasting turkeys at the back/down side of the transmission and catch the fluid as I loosen the bolts. The gasket comes with the filter kit so the gasket is changed every time.

I can almost walk under the Silverado and remove the pan bolts. Looks like a turkey roasting pan will work well here also.

2005 was my last high mileage year. According to my records, I changed oil and filter 8 times and transmission fluid and filter 1 time. This cost me $257.05. I consider that reasonable for 100% mechanical reliability and peace o mind.
 
Originally Posted By: tropic
In a nutshell: am I doing any harm to my engine by running a 0w-30 motor oil rather than the 5w-20 Honda specs in the U.S.?


I used Wally-world Super Tech 5W-20 on my 1st fill just a few months ago. 2008 Fit. It's was like $2/qt. Buddy of mine is a Honda Master Mech and swears by it. I'll test it soon and find out. I asked him about using 0W-xx oil and he said not a good idea. Said the clearances are designed for it and you'r taking a pretty good risk.

Unless you have some data that proves it save lots of fuel, I'd look harder for an affordable decent 5W-20
 
It won't save a drop of fuel unless you routinely see -35F ..and then it's questionable.

When is a 5w-20 not in a 20 grade?

Whenever it's above 9.3Cst.

How often is that?

Every time you start it up cold.

What is it then?

Typically above a 70 weight.

Wow. I never realized it.

What's a 30 grade under the same conditions?

Typically above a 70 weight.

So, you mean that both are WAY over EVEN a 50 weight at some point in the warm up process?

Yes.

Well, so much for the clearance theory.

Exactly.
 
Originally Posted By: quick_16
Originally Posted By: tropic
In a nutshell: am I doing any harm to my engine by running a 0w-30 motor oil rather than the 5w-20 Honda specs in the U.S.?


I used Wally-world Super Tech 5W-20 on my 1st fill just a few months ago. 2008 Fit. It's was like $2/qt. Buddy of mine is a Honda Master Mech and swears by it. I'll test it soon and find out. I asked him about using 0W-xx oil and he said not a good idea. Said the clearances are designed for it and you'r taking a pretty good risk.

Unless you have some data that proves it save lots of fuel, I'd look harder for an affordable decent 5W-20


According to XOM and Amsoil 0W-20 can be used as a direct replacement for 5W-20 without any issues. Even at 75* the 0W-xx oil will flow faster than a 5W-xx. At least this is what I was told by XOM, Amsoil, and Pennzoil reps. I specifically asked about clearances and they said the 0W-xx was the better choice, but advised to stick to the manufacturers requirements in the event of a warranty issue. This can get confusing..........

Frank D
 
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