I would rather be well-respected than popular, if that means having to worry about hurting someone's feelings when I am just laying down facts. I never said there were no oher 90w's out there, although the Schaeffer had too high a pour point, and lacks the EP additives that LE607 has, which, as several have pointed out (besides me), has additives that work at all temperatures.

Red Line makes a fine 75w90. I have 6 quarts of it in the garage. And about a gallon of Amsoil 75w90, 2 gallons of MTL, 2 gallons of Amsoil 10w30, a case of Motorcraft 5w20, well you get the picture.

But we are dealing with apples and oranges here. Red Line does not have the load bearing capacity of LE-607. It's other stats are excellent. If I had the need for a multi-vis diff oil, it is likely what i would use. Why don't some of the proponents of 75w90 write to Honda and get them to change their recommendation?

 

Just a comment from an unbiased observer.

[QUOTE]Originally posted by RED MX5 BTW, I didn't say that the S2000 was exotic,

 

Modifry:

None of what you posted is surprising to me - it is great info. Your research is practically exotic.

As I posted previously, I would not expect LE607 to lower diff temps markedly, although it might at elevated ambient temps, and track conditions. First, its heavier viscosity at all temps will cause it to generate its own heat rise, from inertial effects (the heat generated when the molecules of this viscous fluid roll over one another). Second, synoils generate less inertial friction, as their lighter, mono-molecular structures tend to slide over one another more easily, reducing the self-generated heat.

But you are measuring on the diff housing, so you may be measuring not only the lube temp, but the effectiveness of the lubricant in exchanging heat to the aluminum case. I would also expect a synoil to do well in that regard, as they tend to acquire and give up heat more readily than mineral oils. However, the spikes you saw with the Red Line might be caused by friction in areas of the temperature range where the "common additives" are not as effective as the less temperature sensitive Almasol.

RS2000: You make a good summary. But in every other car I own or have owned, there is a table of various approved viscosities. For my Subaru, the engine oil can vary from 5w30 to a 20w50! For the diff, they range from 75w90 on up. Even the S2000 has several engine oil recs: 10w30 and 5w40. One of my cars allows the use of 90w only down to 32degF! Yet, Honda has one and only one rec for the S2000's differential. There has to be a reason. Honda is very precise in all its fluid recommendations: you have to use their power steering fluid, theys pecify DOT3 for the brakes, MTF for the tranny, their coolant, and strongly recommend their ATF for their auto transaxles. It is logically difficult to support that they have "messed" up since 1999 on the S2000 - they could have prevented having to issue the TSB in 2001 had they found that a multi-vis was ideal, but did not. And has anyone seen a re-issue of that TSB? Not me.

But while lowering diff temps below a critical level is important to longevity, it is less of a factor than wear. It is in that area where LE607 should do well.

It would take a gear expert to have access to a number of "failed" gears to see what typically causes the failures of S2000 gearsets - but since Honda has stuck with 90w, one has to infer that they recognize gear oil film strength to be important. Perhaps the diffs fail because the case or the trans (in the pre 2004's) flexes; perhaps they fail from extreme temps; but if they fail from wear induced by the lube's failure to adequately maintain a protective film under boundary conditions (when the oil cushion is gone, and all that remains are the EP additives), then LE607 or any other oil with high boundary lubrication performance may save the day. I guess we will see.

Your "legal" theory makes sense in only one direction. From 0deg up. But if someone had a failure because the lube seized up, wouldn't Honda be liable for not stating the various temps/gear vis recommendations they do for every other vehicle they make, and which all other mfrs do? If it works in only one direction, I doubt that legalities have anything to do with it. I think you hit upon the salient issue in paragraph 5 of your last post.

Finally, let's also consider that not every S2000 owner reads this Forum, let alone UTH - there have to be 100's, perhaps 1000's of people driving in very cold climates in the US, Europe, and even Siberia with Honda's factory fill in the diff - but has anyone heard of massive failures? Has any onwer of a 2000 S2000 received a notice from Honda in the mail "warning of peril" for not using 80w90 or 75w90 per the infamous TSB? If they have, no one to my knowledge has spoken up. From that i infer that the issue is a non-issie to Honda, they know what they are doing, and the TSB was issued for dealers who could not or would not figure out things for themselves. Had it been an issue of safety or to avoid costly warranty claims, Honda would have done more than issue a TSB 3-4 years ago.

 

You know what?

what fluid comes with the car from the factory? is it 90w?

wouldn't that be interesting to know...can wood work find out?

Road Rage - ur checks in the mail. Thanks for your patience.

Jeff

 

Good points, RR.

I think Honda decides to keep its recommendation at SAE 90 under the assumption that differential will spend most of its operation life-time running above 0C, and likely below 100C. It's a safe assumption because realistically, how long does the differential stay below 0C v.s. above 0C ? Not to mention that the differential is so small, I found it hard to believe any oil won't get to the necessary parts after a mile of driving. Based on that assumption, SAE 90 will offer the best overall protection for the differential.

Now if they also recommend 75W90, the equation could change for Honda because 75W90 offers less protection than the SAE 90 above 0C, below 100C. With the differential spending most of the time operating above 0C, lubricating it with oil with less protection directly translates to reduced longetivity and increased failure rates -- i.e. failures sooner. That could also means increase in cost of warranty coverage for Honda - a no-no for them.

Thus, from Honda's perspective, 75W90 should and will only remains in the service news. But who knows, only time would tell.

 

[QUOTE]Originally posted by nsx555
I don't think RR is one of the most popular guys on the forum, but he does make sense when talking about oil.

 

[QUOTE]Originally posted by RS2000
Good points, RR.

 

RR, are there any specs available for the LE 607 that describe its characteristics for the four ball wear test, noack volality, etc.? I couldn't find these stats. in the LE 607 data sheet. Would be difficult to compare without these figures.

In an environment when it would take 22 mins for the 607 to pour, I would have gotten 200 huskies to pull my sled instead of the S2000

 

[QUOTE]Originally posted by RS2000
RR, are there any specs available for the LE 607 that describe its characteristics for the four ball wear test, noack volality, etc.?

 

RR "Perhaps you could locate a lab willing to run those ASTM tests that interest you - if you do, why not share the results? I am all for finding the best oil for every lubricated part in our cars, ...."

I couldnt have said it better myself!


Also, I have heard from a friend that Amsoil has a "Turbo Approved" oil 10-30 fully 100% synthetic... anyone hear of that? Is it any different than their regular synthetic 10-30 motor oil? I am scheduled to take delivery of 4 gallons of the stuff friday.