RS2000

What's the latest consensus on the narrow list diff oil to use for the S2000?

My inventory of LE1605 ran out unfortunately and I need to pick a new one. From reading more recent threads, it sounds like folks are trying out new ones with a few old favorites like Amsoil still around:

• Amsoil 75W140 (27.7 cSt 100C, 177.1 cSt 40C) - Formulated for the severe operating conditions of today’s pick-up trucks, SUVs, heavy equipment and other hard-working vehicles, recommended for GL-5.
• Mobil 75W140 (24.4 cSt, 170 cSt) - Recommended for use in modern high performance vehicles like sport utility vehicles, vans and light duty trucks requiring API GL-5 performance. 24.4 cSt is closer to max of the original SAE 90 13.5-24 Cst but Amsoil says it failed to meet low temp requirements.
• Redline 75W140 (27 cSt, 192 cSt) - Popular for cars and light trucks like Ford Mustang and F-150, Toyota Tundra and Sequoia, Jeep Cherokee and Dodge Ram. Exceeds GL-5, and recommended for GL-6.

Looks like Redline is the better one purely on paper, with its 192 cSt cold, exceeds GL-5 while also recommended for GL-6, marketed more towards car/racing applications with reasonable retail availability.

Also, is multi-grade a good/better choice vs straight SAE 90 (110 now) ? According to recent threads & articles e.g. this, I saw, while the diff itself has a wide range of tolerance, better cold flow is good for axle, pinions/rings/bearings, etc.? LE 607/1605 worked fine for me for about 100k miles/20+yrs.

[Updated: Found the product sheet for these for record/reference]

• LE607 (20.96 cSt, 235.5) - the original
• LE1605 (21.2 cSt, 229 cSt) - replacement of the original
• Duolec 1605 (20.8 cSt, 231 cSt) - the new, no GL-5 cert

starchland

What is your justification for running 140w

Slowcrash_101

Tribodyn 75w-140 gl5 costs the same as full synthetic mobil 1 75w-140 and harder to find. But it's blue, and everyone knows blue is the most scientifically advanced color.

Slowcrash_101

Even a brand new diff has no issue using 75w-140 gl5 gear oil. I've been using 75w-140 for 8 years now with good results.

Chuck S

SAE 90 gear oil was split a couple years ago into 90 and 110. New 90 being the lower half and 110 the upper half of Old 90. To me this means 110 is OK. I see no reason to not use a multi-grade so 75-110 or 75-140 should be good.

LE has a replacement gear oil but they don't certify it as GL5. I have some in the garage but can't get to it until the end of the week. It was only available in bulk but a vendor decanted it into quart bottles. I'll post the information -- if you want to wait a couple of days.

-- Chuck

Thomas Guide

Amsoil 75W110

Emil St-Hilaire

Redline 75W140.

SlowTeg

Is LE1605 not available anymore? I still have a bunch of quarts in my garage I've been slowly working through.

boyguan

i run amsoil 75-140

darcyw

amsoil severe gear 75w110. I usually tow a tire trailer, autocross, tour and put on maybe 6500 kms/yr. I change diff oil annually.

darcy