75-90 vs. 75-140 diff fluid.

[narksuwan]

What's the purpose behind these 2 grade? I drive long distance ~1,500 both way about 2x per month. Which oil would you recommend? This is Mobil 1 syn gear oil for my differential. Thanks.

[BamZipPow]

Yer probably better off asking over at www.bobistheoilguy.com instead...

[Jayota]

What is the temperature range in which you live in?? 75-90 is fine. I would only recomend the 140w if you have an automatic locker.

[narksuwan]

Originally Posted by Jayota

What is the temperature range in which you live in?? 75-90 is fine. I would only recomend the 140w if you have an automatic locker.

Here in Cali is around 90F but I sometime works in different state which can get triple digit, 115F in Las Vegas last month. I think I'm just gonna use 75-140 because I just found 1 bottle in the garage. Now I'll need 2 more. Thanks

[knj27]

Either will work I suppose, but I'd be willing to bet if you looked in your owner's manual 75w-90 would be recommended for your temperature range.

[fourwd1]

Since Toyota specifies straight 80W or 80W-90 for multi-viscosity for diffs, I don't see how "either would work". Of the 2 mentioned, 75W-90 would be the closest to spec.

[knj27]

Either would work in the sense that they would both lubricate the gears. Of course the factory recommendation is...recommended.

[fourwd1]

I guess that's why they don't reccomend ATF either

[knj27]

Good point