I bring my 98 4-cyl Accord to Honda dealer for regular oil change. Lately, they started use 5-20 oil for oil changes for all the cars. The advisor told me that unless I explicitly tell them otherwise, they will be using 5-20 oil as default.
My question is: Since my car is not new(7 years, 105K miles), can I still use 5-20 engine oil? Will it offer less protection than
5-30 or 10-40? After all, 5-20 oil is newer and more expensive.
Some people tell me to switch to 10-40 oil as car ages. When should I be switching to that grade?
I would just go with what the dealer recommends. that's usually the best thing. i'm wondering about that weight of oil myself because i have a real old civic that calls for 5w-30 and i wonder if it would be better with
I would go with whatever the manual specifies, irregardless of what the dealer says. I assume it is not under warranty, so if anything goes wrong, the owner foots the bill.
I would use whatever grade your original manual calls for, which is probably either 5W-30 or 10W-30. I am not aware of Honda recommending the application of 5W-20 to vehicles which did not originally specify it.
10W-40 was common in older cars, which tended to become oil-burners with age. It doesn't flow as freely as 5W-30 so it doesn't lubricate quite as well. All things being equal, all viscosities would be fine. It is the film strength, not the viscosity, that provides the wear protection. But low viscosity helps the oil actually get to where the lubrication is needed, so in the real world of modern engines it lubricates better. I agree with the others, though; if Honda felt 5W-20 was the right choice they would have specified it.
Changing to 10W-40 in a Honda is an end-of-life move; an acknowledgement that something has already gone wrong (like an inadequate air filter being used for too long, or too infrequent oil changes) and the engine is being nursed along another year or two. Improvements in engine production have ended the oil consumption problem in most engines.
Here is what I learned about the chemistry of motor oil about 8 years ago (I needed the information for a technical paper). The information may be out of date, but I would think it still applies.
So called multiviscosity oil (a misnomer) contains hydrocarbon polymers. Polymers are molecules built around long chains of carbon atoms, maybe 100 or so atoms in the chain. Plastics are polymers. DNA is a polymer. Polymer just means a long chain of similar units.
These long molecules are tightly coiled up at low temperature (due to hydrogen bonds) but at higher temperatures, the molecules uncoil and get tangled together. This "tangling" effectively gives the oil a higher viscosity and is what causes the viscosity of the oil to remain higher as the temperature is increasaed.
The problem is, as I understand it, that for oils with a wide difference between low and high temperature viscosity (such as 10W-40) such a large quantity of polymer must be added that the polymers begins to gunk things up. So it is best to stay with an oil where the two numbers are closer together.
My Honda owners manual recommends 5W-30, but allows 10W-30 in certain temperature ranges. Down here in Texas (where the temperature right now is 81 degrees) it never gets cold enough to neede the lower viscosity oil, so I always insist on 10W-30. The polymer problem MAY be why Honda and other manufacturers have gone to 5W-20 as a recommendation.
On the other hand, there are many characteristics of motor oil that are a lot more important than actual viscosity. As another poster has said, these include such things as film strength, ability to hold contaminants in suspension, etc. Modern motor oils are far superior to the stuff I had to pour in my car 50 years ago and are an important part of the reason why automobile engines can easily go 200,000 miles or more with no problems.
Just my $0.02 worth.
Elliot Richmond Freelance Science Writer and Editor
Hmmm... I actually answered Elmo's post where he stated that there was no such word etc .... So I used the same "error", by using a similar "not correct word". HTH.
for the right price i would use the more advanced motor oil 5w-20. more than likely it is a better oil for your car. your owners manual was written before that oil was even thought of probably and now it's out and if your manual could be rewritten it may actually be calling for w20. i wouldn't worry about it. if the car is running good and you talk to the dealer and they tell you its a better oil. than you can use it.
Well said! As oils evolve Honda has changed reccomendations that may differ from your owners manual. The industry specifications continue to change and as oils improve they become better for your vehicle even though they may be a different weight.
The two weights are usually the same or very similar in price. There is no one who knows your vehicle better than your dealer. There is no advantage to your dealer to reccomend one over the other, but he has an incentive to give you the right service to maintain you as a customer. There is an official Honda chart that you can ask to see, that will show you what Honda reccomends for your vehicle. I think you will find that your dealer is providing the correct weight of oil for your Accord.
Certainly I would use the latest SM / GF-4 rated oils, but oil quality and oil weight are two different things.
Ford went to considerable trouble to publish service bulletins showing which older models were demonstrated to be compatible with 5W-20 after Ford switched most of their new vehicles to 5W-20. However, I have never seen any similar publication from Honda, which makes one wonder if there are issues with using 5W-20 in Hondas which did not specify it when new.
By the way, Ford stated that the primary reason for using 5W-20 is for improved fuel economy over 5W-30 and bragged about the expected 0.6% improvement. Somehow I don't think any of us would ever be able to detect a less than 1% fuel economy improvement.
You bring up an interesting point regarding the use of "lighter" engine oils as relates to mileage goals.
The question in my mind is, "Are the current materials used in engine internal parts such as pistons, valves, crankshafts, engine blocks, camshafts etc. substantially the same as say an early 1980's Honda?"
My 2001 owners manual says "5W-20 oil is formulated for year-round protection of your Honda, to improve cold weather starting, and to help your engine use less fuel". Is Honda only concerned about cold weather? What about extreme hot weather? Does a 5W-20, 5W-30 or 5W-40 not have the same cold weather protection? I would prefer hot weather protection also. I think the main reason for recommending this oil is as stated to "use LESS FUEL". Any comments?
============================================================================== TOPIC: 5-20 oil on 98 Accord-I4?
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5W-20 oil is not "more advanced" than 10W-30, it's just a different viscosity.
Stick with the viscosity specified for your car. It is safer to err at a higher viscosity.
There are idiots, but it's not Ford's engineers who don't know what they are talking. And, they "cut corners/save money" doesn't make sense if they "went to considerable trouble to publish ..."
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