1997 Civic Oil Viscosity

[jkv357]

Originally Posted by euromodder

Sure. It flows better when cold.
Warm performance is the same though (W30).

They are claiming it flows better even when hot (30), giving up to a 2% increase in FE.

I don't understand how both could be rated at 30-grade, but flow differently at the same temp.

Any ideas if that's true/possible?


Jay

[ZOMGVTEK]

It can get well below freezing here, and I run the recommended 5w20 year round. My last two UOA's were poor, but I hear the J30A1 tends to be a high wear engine. I somewhat recently started trying to get better MPG just because I can, and my engine uses no noticeable oil now. I used to burn .5-1qt per 3K, and then would change it when the level got to the bottom dot. I have 4K on it now, and it didn't budge from the top dot, which has never happened before. Same Penzoil Platinum 5w30 + Puralator PureOne w/ FilterMag RA300 as always. I'm probably going to be doing a oil change and send a sample to Blackstone this time around.

[California98Civic]

Originally Posted by ZOMGVTEK

It can get well below freezing here, and I run the recommended 5w20 year round. My last two UOA's were poor, but I hear the J30A1 tends to be a high wear engine. I somewhat recently started trying to get better MPG just because I can, and my engine uses no noticeable oil now. I used to burn .5-1qt per 3K, and then would change it when the level got to the bottom dot. I have 4K on it now, and it didn't budge from the top dot, which has never happened before. Same Penzoil Platinum 5w30 + Puralator PureOne w/ FilterMag RA300 as always. I'm probably going to be doing a oil change and send a sample to Blackstone this time around.

This discussion has made me revisit this again. Contrary to what O'Reilly Autoparts told me, I am reading that 0w pumps better at below-zero temps and behaves the same as its 30 or 20 weight counterparts with a 5w (source). Why isn't 0w always better, since better pumping at a cold start seems like it would always be better? BTW, the cited source claims Group 4 PAO based synthetic oils are the best for FE--as I think aporigine says in post 2 or 7 above.

[PaleMelanesian]

I use Mobil1 5w20 in my Civic. Mobil because it's easy to find and high quality. (I'm not arguing which is best, but it is good). 5w20 because it's what the other car takes and I stock only one bottle in the garage. A little mpg bonus from freer-flowing oil can't hurt. My commutes are short and most of the way is a "cold" engine so the 5w part applies more than the 20/30 part.

I switched to synthetic and the lower viscosity at 150,000 miles and it still doesn't burn any. Now at 188,000 miles.

[aporigine]

"Why isn't 0w always better, since better pumping at a cold start seems like it would always be better?"

It's a question of longevity. To get a 0W-30 rating, you need more VI (viscosity improver) polymers in a somewhat thinner base. These don't last as long as the base oil, and after some thousands of miles (varies depending on the engine design, the individual engine's quirks and the driving style) you're effectively running 0W-20.
If you change your oil early and often, you get the benefits.
If you go for longer change intervals, the oil with less VIs will keep on doing what it was designed to do ... until something else ages to the point where an oil change becomes necessary.
cheers apo

[jkv357]

Originally Posted by aporigine

"Why isn't 0w always better, since better pumping at a cold start seems like it would always be better?"

It's a question of longevity. To get a 0W-30 rating, you need more VI (viscosity improver) polymers in a somewhat thinner base. These don't last as long as the base oil, and after some thousands of miles (varies depending on the engine design, the individual engine's quirks and the driving style) you're effectively running 0W-20.
If you change your oil early and often, you get the benefits.
If you go for longer change intervals, the oil with less VIs will keep on doing what it was designed to do ... until something else ages to the point where an oil change becomes necessary.
cheers apo

I understand what you are saying, but doesn't a synthetic oil have less of an issue with that type of viscosity breakdown than a conventional oil?

I was under the impression that synthetics don't use VIs the same way conventional oils do.


Jay

[California98Civic]

Originally Posted by jkv357

I understand what you are saying, but doesn't a synthetic oil have less of an issue with that type of viscosity breakdown than a conventional oil?

I was under the impression that synthetics don't use VIs the same way conventional oils do.


Jay

The source I cited in post #13 above claims Group 4 PAO based synthetics do not need VI additives. It is the Group 3 types, of which Mobil 1 is an e.g. (though a good oil that I am running right now) that need them because they are not strictly absolutely synthetic. Group 4 synthetics should not, therefore, have this break down problem, no?

[jkv357]

Originally Posted by California98Civic

The source I cited in post #13 above claims Group 4 PAO based synthetics do not need VI additives. It is the Group 3 types, of which Mobil 1 is an e.g. (though a good oil that I am running right now) that need them because they are not strictly absolutely synthetic. Group 4 synthetics should not, therefore, have this break down problem, no?

Not sure...

This info from aporigine, post #7, puts Mobil1 in Group 4 -

"Mobil 1, same weight, is largely group 4 PAO. Its numbers are 165 and -65 deg C. Additional factette: M1 5W-30 needs no viscosity improvers (those long gelatinous shear-sensitive molecules that allow formulation of wide weight ranges) to achieve 5W-30 spec"


Jay

[aporigine]

I had a long answer typed out but I just blanked it. I've been looking up viscosity index improver chemistry, expecting to find a single class of molecules being the major article of commerce.
It ain't so.
VIIs in general are plastics. Two examples I've found are ethylene propylene polymer, and polyalkyl methacrylate. (Polymethyl methacrylate is Lucite/Perspex). Those two families alone have very different responses to thermal and mechanical stress. Early VIIs had short service lives, leading to definite degradation of HTHS (high temp, high shear) viscosity after a few thousand miles, and some even produced a waxy residue on bearing surfaces.
Bottom line is that I need to amend my "old wisdom" in re VIIs. There seem to be some that have excellent stability and benign behavior once degraded. Finding out what's what is made a bit of an adventure because oil formulators/sellers treat the hard info as proprietary. I expect that a basic group 2 oil sourced from certain far East producers will contain traditional, flawed but dirt-cheap VIIs. Caveat ecomoddor!!

I would expect that a premium oil using a group 4/5 base stock also uses advanced VIIs. I don't have info on whether or not this is so. In a wide-spectrum multigrade, VII makes up typically ten per cent by weight of the finished oil. Concentrated VII is not as good a lubricant as base stock, so as a mileage-obsessed traffic barnacle I will seek oils that use less of them. That's what choosing certain products using a blend of PAO and ester gain me. A longer recommended change interval is pure bonus.
cheers apo

<edit> I have been finding contradictory info on M1's base stock:
1) It has always been and continues to be based on group 4 PAO.
2) It was PAO but is now largely group 3 mineral-sourced.
If anyone has the definitive word w/relevant link ... thanks in advance!!

[RandomFact314]

I went and got the Mobile 1 high mileage and the Purolator PureOne oil filter. Got a new drain plug too, just because.

Checked my oil while I was there and it was ultra low, Put in a quart I had at the house.