Understand Motor Oil

[07exlowner]

I've been comparing two different motor oils from the same company, Mobil 1 5W20 and Mobil 1 Extended Performance 5W20, for my next oil change. While I'm sure both products are very good (and perhaps very similar), I'd like to know whether one is really any better than the other.

I came across the following information on the official site. The numbers seem close but different between the two, but what does this all mean? Can anyone explain these numbers?

Mobil 1 5W-20
SAE Grade 5W-20
Viscosity, ASTM D 445
cSt @ 40º C 48.3
cSt @ 100º C 8.8
Viscosity Index, ASTM D 2270 163
Sulfated Ash, wt%, ASTM D 874 1.0
HTHS Viscosity, mPa·s @ 150ºC ASTM D 4683 2.62
Pour Point, ºC, ASTM D 97 -47
Flash Point, ºC, ASTM D 92 228
Density @15º C kg/l, ASTM D 4052 0.80

Mobil 1 Extended Performance:
SAE Grade: 5W-20
Viscosity, ASTM D 445
cSt @ 40ºC: 47.4
cSt @ 100ºC: 8.9
Viscosity Index: 171
Sulfated Ash, wt%: 1.0
HTHS Viscosity, mPa·s @ 150ºC: 2.7
Pour Point,ºC: -51
Flash Point,ºC: 235
Density @15º C kg/l: 0.86

I'm considering the latter because I intend on sticking to the maintenance minder (which means I won't be changing the oil every 3-5k miles) and somehow the "extended performance" and "15,000 mile guarantee" makes me feel better (although it's probably a marketing scheme). But is there really any difference numbers wise?

I know I could probably make this easier on myself by just picking either one and not even bothering to learn about any of the numbers above, but then being the "scientist" in my family, I do like to know exactly what it all means. Plus, it makes this forum more interesting! :D

By the way, what exactly does 5W20 mean? I understand it has something to do with viscosity, temperature, etc., but what do the actual numbers represent? For example, what's the difference between 5W20 and 5W30, or 5W30 and 10W30?

Thanks!

[2RedV's]

Either oil is perfectly fine for your CR-V.

The only marketing gimmick is that you have been led to believe that modern vehicle engines require 3-5k mile oil changes when using conventional oil. If that were true, why is it that so many Honda's run to 300,000 miles or more using conventional oil, changed only when the person remembers to change it?

[Davecr-v]

I just dropped my car off today to do an oil change and alignment. I think it has more to do with driving style and frequency. For example if you live in the country drive a couple of miles every few days and you are on empty highways your engine isn't going to have as much stress as mine which is driven almost everyday about 50 miles on crowded highways and rough city traffic. I prefer to drop the car off at my mechaninic because although it taes time as a result of his limited space and the fact he has more work to do. I know A real mechanic who knows what he is doing is changing my oil over some highschool kid getting paid minimum wage at a big oil place.

[tsmithvt]

By the way, what exactly does 5W20 mean? I understand it has something to do with viscosity, temperature, etc., but what do the actual numbers represent? For example, what's the difference between 5W20 and 5W30, or 5W30 and 10W30?

Thanks!

The two oils are virtually the same. The "Extended performance" has a slightly lower pour point and a slightly higher flash point. The pollution qualities are identical. The ASTM (American Society for Testing and Materials) notations are the test methods used.

The first number in 5W20 is the SAE cold weight and the second is the hot weight. For a much more complete explanation use the link below.

http://www.maintenanceworld.com/Articles/thibault/HowToRead.htm

[GoHack]

By the way, what exactly does 5W20 mean? I understand it has something to do with viscosity, temperature, etc., but what do the actual numbers represent? For example, what's the difference between 5W20 and 5W30, or 5W30 and 10W30?

Thanks!

5W20 - Means in cold temperatures the oil will operate, or pour as a 5 weight, (W means Winter Weight), while in warmer temperatures, it will operate, and pour as a 20. Synthetic oil can pour at much lower temperatures than mineral based oil can, as well as withstand higher temperatures, w/o breaking down. I don't have the exact temperature range.

The differences between the 5W20 and 5W30, is just the upper weights, w/30 being heavier than the 20, while w/the 5W30 and 10W30, it's the winter weights, w/5 being thinner than the 10.

Unless your Honda manual specifically asks you to use the 5W20, I'd go w/the 5W30. If you do use the 5W20, I'd go synthetic, since it is a much more durable oil than mineral based oil is.

I live in the northwest, in Washington state, where it can be below zero in the eastern part of the state, while at the same time, being in the 40's, in the western part. I myself use synthetic 0W30 year round in my BMW 330Ci, w/no problems. The '99 Porsche 996 I use to own, used a Porsche recommended Mobil 1, 0W-40 year round.

The synthetic 0W30 oil I use, also seems to work OK in my CR-V, which I just got, after using it for almost 3000 miles, w/o needing to add any oil to it.
.

[2RedV's]

Just spend the approximate $20 to have an oil analysis done and go from there. The vast majority of vehicles will perform (and last) just fine on conventional oil with 5-10k mile oil change intervals. Why protect the engine so it lasts 300,000 miles if the rest of the vehicle won't?

[Badgerland]

Just spend the approximate $20 to have an oil analysis done and go from there. The vast majority of vehicles will perform (and last) just fine on conventional oil with 5-10k mile oil change intervals. Why protect the engine so it lasts 300,000 miles if the rest of the vehicle won't?

While I agree with your first statement, the second part doesn't really make sense. There are good cases of Honda's going well past this mark with proper care and maintenance.

http://automobiles.honda.com/mile-makers/story.aspx?Story=42

JMMV:)

[2RedV's]

While I agree with your first statement, the second part doesn't really make sense. There are good cases of Honda's going well past this mark with proper care and maintenance.

http://automobiles.honda.com/mile-makers/story.aspx?Story=42

JMMV:)I am talking about the typical Honda owner in which they feel that proper maintenance is oil changes, nothing else until it breaks.

[Badgerland]

I am talking about the typical Honda owner in which they feel that proper maintenance is oil changes, nothing else until it breaks.


Well HOPEFULLY the "typical" Honda owner knows that proper maintenance is more than oil changes...I think that constitutes as vehicle abuse!:eek: I would presume that the good folks here are more interested in doing the right thing to their CRV.

[2RedV's]

Well HOPEFULLY the "typical" Honda owner knows that proper maintenance is more than oil changes...I think that constitutes as vehicle abuse!:eek: I would presume that the good folks here are more interested in doing the right thing to their CRV.
If you read thu past posts you will notice a disturbing trend of numerous people who say "My last Honda was so trouble-free, it only needed oil changes and nothing went wrong."

Yikes. Don't buy a used car from one of those people.

[Badgerland]

If you read thu past posts you will notice a disturbing trend of numerous people who say "My last Honda was so trouble-free, it only needed oil changes and nothing went wrong."

Well we hope that those folks are the minority and not the majority! :rolleyes:



Yikes. Don't buy a used car from one of those people.

I totally agree.

[dradave]

Anything you need to know about motor oil and other vehicle related fluids can be found at: http://www.bobistheoilguy.com

[sleeksilver]

Anything you need to know about motor oil and other vehicle related fluids can be found at: http://www.bobistheoilguy.com

Great resource....

[taffy08]

So I have been following this oil discussion and have several questions that come to mind. I have had Honda products way back into the 70's, motorcycles, lawnmowers, and three cars. So with each of these products came a manual, or service manual and if you look at the temperature gradiant with the oil viscosities layed over the top you see that as the temperature range at which you are using your vehicle rises so does the viscosity of the oil . I understand about straight mineral oil, and synthetics and multi-weights and what they all are advertised to do, but temperture is still a factor in operating your vehicle. Some of the manuals say, to use the weight of oil at which you expect to be the average temperature during the time interval between oil changes. So my point is you look at the owners manual for the new 07-08 CR-Vs and they say use 5W-2o acroos the whole temperture range. Going back to those temperture gradiants 5W-20 starts at 20-30F and heads down to -20F. 5W-30 starts at 30-40F and heads down to -20F. On the other hand 10W-30 starts around 0-10F and goes up to 85-90F. I know why Honda wants to use this lighter oil for energy conservation etc. but when you drive your CR-V during July-August and it gets 85-100F I think I would be real concerned about using that light of oil at those tempertures. I have not decided what i am going to do when late spring-summer rolls around but I am looking at alternatives to 5W-20 during the summer run.

[Black Pearl]

Welcome to the club. It is my understanding that Honda switched recommendations to 5W-20 a number of years ago (2002 according to the CR-V owner's manuals, but I don't know if that is across the board). So there should be a fair amount of operating history using this weight of oil. The popular explanation is that Honda did it for fuel conservation. I find that a bit far fetched. It may be a factor, but I doubt that was the only reason. I am stretching a poor memory here, but I seem to remember reading something that the lighter oil worked better in the precise passages needed for the variable valve timing components.

Personally I am reluctant to not follow Honda's recommendations, but I also live in an area that doesn't have extreme heat. I have this possibly naive belief that Honda should know best. If one looks at the rear differential oil change recommendation for the 06 and prior years, that faith gets severly tested. I doubt that changing to 5W-30 for the hot months is going to harm anything, but then again, there is a lot going on in an engine and conventional wisdom does not always hold true.

A posssible option is to use a 5W-20 synthetic. It has the same weight, but better high temperature characteristics. Although many on this forum will tell you that conventional motor oils are good enough, and a synthetic is a waste of money.

Another consideration, how long do you intend to keep the car? If you don't keep cars for a long time, why concern yourself with oil?

In the end you have to do what makes you comfortable. Opinions are like...well I won't go into that, but as I stated in an earlier post, I am weary of the oil controversies.

In any event, welcome to the club and good luck with your decision.

[2RedV's]

So I have been following this oil discussion and have several questions that come to mind. I have had Honda products way back into the 70's, motorcycles, lawnmowers, and three cars. So with each of these products came a manual, or service manual and if you look at the temperature gradiant with the oil viscosities layed over the top you see that as the temperature range at which you are using your vehicle rises so does the viscosity of the oil . I understand about straight mineral oil, and synthetics and multi-weights and what they all are advertised to do, but temperture is still a factor in operating your vehicle. Some of the manuals say, to use the weight of oil at which you expect to be the average temperature during the time interval between oil changes. So my point is you look at the owners manual for the new 07-08 CR-Vs and they say use 5W-2o acroos the whole temperture range. Going back to those temperture gradiants 5W-20 starts at 20-30F and heads down to -20F. 5W-30 starts at 30-40F and heads down to -20F. On the other hand 10W-30 starts around 0-10F and goes up to 85-90F. I know why Honda wants to use this lighter oil for energy conservation etc. but when you drive your CR-V during July-August and it gets 85-100F I think I would be real concerned about using that light of oil at those tempertures. I have not decided what i am going to do when late spring-summer rolls around but I am looking at alternatives to 5W-20 during the summer run.Welcome to the forum! :) (and a good first post, at that)

You have to begin thinking in modern engine design. These are not the engines of the 70's. Modern (1995+ or so) engines are so much more efficient and capable of maintaining a more even internal temperature despite any temperature extremes, that different grades (viscosity) of oils are no longer needed.