psychoazn

UOA for for LE 1605. This sample included 3 track days, ~1500-2000 miles of back roads, and my daily drive of 7 miles.

Diff and engine are both stock.

Unfortunately I don't have a virgin sample to compare this with.

Previous two changes are with Motul Gear 300 (75w90). The LE is a straight 90 weight.

The first sample (furthest right) included a LOT of canyon/track, as indicated by the really high iron reading, but I'm willing to postulate that the diff may take a while to break in.

SpitfireS

LE 1605 is a single grade SAE 110.
It starts at 21.1 cSt so it does shear, and it did shear out of grade to below 18.5 cSt.
Nevertheless iron ppm is the lowest so far. (ppm/mile)
To confirm you should use the Motul gear once for the same milage and see what you get.
But that's almost the same as asking a patient to use that sugar coated vitamin-C instead of the real stuf again

Thanks for posting

(Maybe its time for a UOA section here, you know: all UOA's - engine/trans/diff easy to find)

psychoazn

Ahh its a 110 weight?

I stand corrected; I am using it purely based on recommendation by other s2ki'ers.

I'm currently on 1605 again, but I'll give the Motul another try afterwards since I still have a few bottles lying around.

OT: The 1605 is a rather pretty shade of purple...

Ralleh

Is it true that the heavier weight oils are considerably more toxic/carcinogenic?

spets

FYI, the 110 weight is OK to use. The old SAE 90 spec when the car was designed had a very broad viscosity range. The newer SAE spec created a 110 weight category to cover the upper end of the old SAE 90 range.

INDYMAC

Thanks for posting this UOA. It looks pretty similar to mine. I don't think you are seeing shearing as much as you are seeing mixing with the lighter viscosity Motul 300 75W90. I think your next UOA will be more reflective of how 1605 holds its viscosity. Her is my last/first UOA of 1605 after using 607:

https://www.s2ki.com/forums/index.php?showt...&#entry16414731

psychoazn

Thanks for the info; I just read through the whole thread at BITOG.

I'm a total noob when it comes to diffs; good to learn new things

zeroptzero

I personally wouldnt go back to the Motul, I mean it's likely a good fluid but there is a straight correlation between viscosity and wear on these reports. Stick with the new fluid IMO as the wear has dropped considerably. In your part of the country that fluid should work fine for you. If you had some cooler weather I'd recommend the Amsoil 75w-110 that I'm running in my car, but not really needed in your climate. Thanks for posting, perhaps I can do a UOA of my Amsoil in a few months time.

starchland

Running the Motul 300v 75w90. 30 bucks a litre! - 14k km on it so far thinking of swithcing it out next season.

Viscosity is def on the high side. Any reason you switched from the Motul?

how do we conclude that suspended iron particles=wear? the fact that the iron has to be coming from somewhere?

dont be surprised by the pretty colours, royal purple looks nice too

INDYMAC

Please do a UOA of the AMSOIL gear oil, maybe after your second fill? Although I'm pretty convinced that the LE 1605 is my best choice for driving conditions here in Texas (a fair weather driving car for me too), I would probably choose AMS 75W-110 instead if I ever had to drive my car in cold arctic weather. I've never seen any testing of it though.