I have an upcoming oil change to do in a neighbor's Mitsubishi and I'm looking for input as to whether I should just stick to the recommended oil or go for something a little heavier?
5w-30 in a 5w-20 engine
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Whimsey
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Rum334,
My mother had me help her select a new car as her old one was fading away. Honda was one she had considered but I explained to her that I'm not comfortable with the thin oil they call for with our rather warm summers. I avoided Ford products for the same reason since their's is a CAFE call only.
Oh, I know about the UOAs, I do them also and while I believe they can be helpful I don't take them as absolutes.
I'm going to be the one maintaining the car for her and I want to be able to use products that I believe in.
To each his/her own.
My mother had me help her select a new car as her old one was fading away. Honda was one she had considered but I explained to her that I'm not comfortable with the thin oil they call for with our rather warm summers. I avoided Ford products for the same reason since their's is a CAFE call only.
Oh, I know about the UOAs, I do them also and while I believe they can be helpful I don't take them as absolutes.
I'm going to be the one maintaining the car for her and I want to be able to use products that I believe in.
To each his/her own.
5w30 in a 5w-20 engine? No problem. Virtually all of these engines called for 5w30 at the time that they were designed. They just magically transformed into 5w-20 engines at about the time the mfrs realized that they needed to do better on their CAFE numbers. Do you think that around 2001, both Ford and Honda suddenly redesigned their engines for 5w-20 and now they build them differently? Not. That said, I'm well satisfied that our UOAs show that 5w-20 can do fine under normal circumstances. I just wonder about what happens when you encounter extremes unexpectedly, such as an overheat or perhaps an FI problem resulting in fuel dilution. I also don't spend a lot of time worrying about this since both my G35 and my wife's Sequoia run absolutely beautifully on thick-30 GC.
Exactly
The 93 Taurus that we have calls for 5W30 or 10W30 for most conditions, but the factory shop manual mentions using 10W40 for a number of things. I guess it was originally designed to use 10W40, and they didn't get around to changing all the references to it.
Did I read that correctly? You did not buy a Honda due to the fact they use 20W oil?
I started a similar thread to this about a month ago. I asked if 5w-20 affected engine longevity. Although many posts were salient and informative, some responded that, essentially, 5w-20 was imposed on the automakers by the government to improve CAFE. This is not an answer to the question. It doesn't matter if the car companies decided to use 5w-20 to improve mileage; I was asking about engine longevity. Anyway, the evidence, both substantive and anecdotal, seems to indicate that 5w-20 does not adversely affect engine wear. Currently, I am running Mobil 1 0w-20 (the old SL stuff) in my '03 Accord. I have 2 changes of Pennzoil Platinum 5w-20 and 2 changes of Mobil 1 5w-20 (the new SM stuff) in my stash. I will probably stick with synthetic and 4k-5k OCIs (a lot of city driving), however, the UOAs on the Motorcraft 5w-20 blend look really good and the Motorcraft is less than half the price of the synthetics. Regardless, I love both my Hondas; both run great using the oil specified by Honda and I'm sorry that someone did not buy one simply because of 5w-20.
You mentioned that this is for a neighbors car. I might suggest you discuss this with him/her and let them decide whether or not to stick with the factory recomendation or use something else.
I never cease to be amazed at the allegations made against Honda and against 5W-20 oil. See the UOA I posted last night for our 02 Accord. Most of that was summer driving at other temperatures, highway speed, engine fully hot for over 98% of the driving. Look at the facts!
You choose to use 5w30 or heavier oil for your reasons, as many have said, that will not harm the engine. But you should also observe the factual evidence that 5W-20 oil does serve these engines properly. Our engine has been on it for all 60K miles, look at the numbers.
You choose to use 5w30 or heavier oil for your reasons, as many have said, that will not harm the engine. But you should also observe the factual evidence that 5W-20 oil does serve these engines properly. Our engine has been on it for all 60K miles, look at the numbers.
FYI...Highway driving is very easy on an oil.
I'm not hard over anti-20, but a few things concern me. First, as to this post, you're not putting "the facts" into perspective. A handful of predictably good UOA does NOT mean that there isn't reason to question the soundness of blanket 20 wt recommendations.
Second, and what really scares me about the stuff is fuel dilution. Coincidentally, the recent good UOA we saw on an Accord using 40 wt oil also showed fuel dilution. What if there had been substantial fuel dumped into a sump full of 5w-20? Regardless of where any one person weighs in on this debate, there IS a point at which oil becomes so thin that it can not protect as intended. 20 wt oils are just that much closer to that point than their heavier counterparts. What about that fact?
OK, so 5W-20 oils are OK. Not necessarily the best, but OK. I'll accept that. What I've not heard anyone say, is what should motivate anyone away from the time proven 10W-30 & 5w30 weights? Will these hurt a "5W-20 engine"? (there is no such thing). I'm not a 5W-20 basher, but why should one change if what they've been using does the job? Don't talk about fuel economy... the difference is not worth mentioning. So many folks have talked about "closer tolerance engines" without even knowing what they're talking about. Close tolerances do not equate to close clearances. I have a machinist background, so I know what I'm talking about. Close tolerance merely means that parts are held to a higher level of quality. They are allowed less deviance from the nominal dimensions on the drawing. Close clearances are just that... less gap between parts. You can have close tolerance parts that fit as loosely as a **** in a shirt sleeve. Now, perhaps some manufacuturers have decided to drop clearances (such as in main bearings) by a tenth (.0001) or so, but considering thermal expansion and such, there's no way engineers can pratically reduce such clearances from the .0015-.0018 which is normal. I have no doubt that valvetrain clearances have been reduced, especially when we're talking about rollerized followers and rocker tips. All I'm saying is, all this talk about 5W-20 being necessary for "close tolerance engines" is pasture pudding. Are modern 5W-20 oils good? Evidence seems to say yes. Does that make them better than 5w30 or 10W-30? No one has been able to prove that, and other threads have evidence to suppport longer engine life with xW-30 oils.
So, I'm willing to admit I'm wrong if anyone can provide clear evidence why 5W-20 provides better engine protection than XW-30.
So, I'm willing to admit I'm wrong if anyone can provide clear evidence why 5W-20 provides better engine protection than XW-30.
I respect ekpolk's concerns. Over time I have seen many good xW-20 UOAs posted here, by many in different engine types not just Hondas. EK- when you say "a handful of precdictable good UOA's", may I ask, a handful in Hondas, or for all vehicles? We have seen many good xW-20 UOAS, have we not?
You raise a valid concern about fuel dilution. Not a problem with our engine so I haven't thought much about it.
I agree there are many fine xW-30 and xW-40 oils. I ran them for years in our 1987 Honda Accord. I'm not a proponent of one or the other. I do think owners of cars specced for xW-20 can have reasonable confidence about the performance of those oils from the evidence we have seen.
You raise a valid concern about fuel dilution. Not a problem with our engine so I haven't thought much about it.
I agree there are many fine xW-30 and xW-40 oils. I ran them for years in our 1987 Honda Accord. I'm not a proponent of one or the other. I do think owners of cars specced for xW-20 can have reasonable confidence about the performance of those oils from the evidence we have seen.
My dad told me in the 50's when multiweight oils came out. He and his friends thought it was a load of crap. "It's either a 10 or a 40 weight. Aint no way it's both!!!"
So along those lines. I do believe the new 20 weights are for other than Cafe. Just because it's new. Does not mean its bad. To not buy a Honda based on the oil it calls for seems crazy to me. But...Thats me. To each is own!!!
So along those lines. I do believe the new 20 weights are for other than Cafe. Just because it's new. Does not mean its bad. To not buy a Honda based on the oil it calls for seems crazy to me. But...Thats me. To each is own!!!
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I don't push any particular viscosity oil. There are some on this forum that seem to push the thinner is better idea. However, I haven't seen one of the big names on this forum push viscosity in either direction. Not one of the big names.
As I said earlier; to each his/her own. I have no problem with what others use.
As I said earlier; to each his/her own. I have no problem with what others use.
Fred Bear,
Is your name based on that one song?
Anyway, the 20 weights ARE just for CAFE.
Ford has stated quietly, but in writing, that 20 weights were introduced to save gas and the environment. The link to the document has been posted on BITOG in the past.
I've read a few academic papers on low viscosity crankcase lubricants. Every one I ever came across cited fuel mileage as the primary reason for their study.
The studies tended to conclude that heavier oils (30 to 40 weight) had the lowest wear rates at real-life operating temperatures. They found 20 weights had higher, but acceptable, wear rates.
5W10s had wear rates that were thought to be unacceptable in most vehicles.
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