Thats funny. Just ordered some 607 yesterday. Guess I'll be using the new stuff on my next change.

 

FYI
In the "old days", in the SAE J306 (gear oil spec), the SAE 90 spec was pretty wide, IIRC from 15cSt to 26cSt or so. (again: IIRC, just to give you an idea)
The revised SAE J306 spec "cut" the 90 weight spec in half and called the upper part a SAE 110.
edit: 13.5 cSt - <24 cSt was SAE 90.
Now SAE 90 = 13.5 - <18.5 cSt.
SAE 110 18.5 - <24 cSt.

The S2000 manual was written in 1999 and in those days the old SAE J306 spec was still the official one.
Without any viscosity spec in cSt there is no telling what Honda specificly meant by "SAE 90"

That said: Do you want to risk your diff with thin oil?

The new LE 1605 is what I want (if I can get it).
Same pour point, a little thicker.

 

SpitfireS;

Are you saying that you now think that LE607 is a little thin for use in the S diff ?

Also one of the selling points of LE607 was the ALMASOL additive in it. Reading LE's documentation it appears that the DUOLEC additive they're using in LE1605 is very similar. Do you know what the major differences are?

 

I find it hard to believe that LE607 is too thin for the S2000. Many, many S2000 owners have logged tons of street and track miles with LE607 with no issues.

The only question up to this point has been whether the LE607 is too thick for winter street use? Anyone who has actually pumped LE607 into their diff knows it appears a lot thicker than the standard stuff people use (Valvoline semisyn 80-90, Amsoil 80-90, Mobil 1 75-90 etc).

I have had no issues with many, many repeated 5k lunches (with 275 hoosier A6 tires).


I will have no problem using up the 4-5 qts of LE607 I have sitting in my basement before getting the new stuff.

 

[QUOTE=trapper,Oct 3 2007, 09:30 AM] SpitfireS;

Are you saying that you now think that LE607 is a little thin for use in the S diff ?

 

[QUOTE=TubeDriver,Oct 3 2007, 10:53 AM]I find it hard to believe that LE607 is too thin for the S2000.

 

The new LE1605 have new additive added to the old LE607...The old LE607 is a very good gear oil...I have over 30k miles using LE607 and no issues with my differential. I would keep using LE607 if they were still available... FYI, i got the LE1605 from a local race shop, all they had was 5 gallon drum..The labels on the LE1605 even states it replaced LE607.

 

LE 607 is virtually the same viscosity (thickness) as the new LE 1605 (SAE 110). It also has the same pour point (-11F). But I think that is where the similarities end. LE 1605 appears to be a totally reformulated industrial/automotive GL5 gear oil. It is a synthetic blend with a completely new additive package and EP ingredient (Duolec). I just hope it actually is an improvement over an already proven winner like LE 607. I trust that LE knows what their doing, I'm just inquiring with you guys and gals in order to verify it's good to go.

 

LE-607 =>
LE-1605 =>
Honda Marine SAE 90 GL-5 =>
80W-90 GL-5 oils => (if there is nothing else)
75W-90 GL-5 oils not in my diff.

That's how I think about those gear oils.

(There are more brands and viscosities, I know....)

Lets go back to the manufacturer:
Honda recommends a straight SAE 90 weight GL-5/6 for the OEM diff.
Simple & a fact.
Why?
Not so simple.
GL-6 never became official.
It was intended to spec oils for high offset, hypoid gears.
(is what we have: the pinion sits well below the center of the ring gear)
In 1999 it (GL-6) was still on the drawingboard.
All this makes me believe Honda doesn't want you to use the "common" multiweight XXW-90 gear oils in the diff.
Remember: we have 240 HP (at the crank.. ok) and it's only a 7" diff.
Ask any dragracer and they will go
The final drive can use all the lubrication it can get.
Straight weight gear oils will shear less, will keep their EP (Extreme Pressure) qualities longer.

Richmond actually recommends a 75W-140 oil for their final drive sets.
LE-607, being a straight 90 weight is IMO good enough for my 4.57, but I will use the LE-1605 for the next change and maybe mix in some LE-1606 if I can get it, to get closer to the SAE 140 spec.
Pour point is almost the same, it will make it a bit higher but IMO pour point is no big issue anyways.
And it isn't for Honda either as they never mentioned anything about outside temps and diff oil.
They do for engine oil btw (5W-40)

If you really have to start & drive your car at arctic temps on a regular basis, diff oil is not the only "oil problem" you have to solve.
Think trans and engine.

I'm far from being a tribologist like RoadRage, I've spend a lot of time reading on BITOG about engine & gear oils and think I can make an informed decision about what oil to use in my engine, trans and diff.
My engine now has Shell Helix UltraX 0W-30 (12200km and counting) its a full true synthetic PAO/Ester oil, the (rebuild) trans has Honda MTF-III (it was available in the Netherlands) and LE-607 for my 4.57-R diff.
I would not hesitate for a second to use LE-607 / LE-1605 in an OEM diff.

Pfff long post......

 

Dam I wonder what makes Mobil1 75W90 tick. The stuff appears as thin as 5w30 it seems. But it has proven itself a long time ago in many s2ks including my own.