Redline Differential Oils

I was looking at changing to Redline in my differentials, and had a question on the 75W90 vs. 75W85.

I know both can be used without problem, and both meet GL-5 specs. My question is what would be the difference? Slightly better mileage with the 75W85? Slightly better high temperature performace with 75W90? Just curious.

Toyota specs 75W85 vs. 75W90 for some reason.

Some links

75W85 (which specifically mentions Toyota)

http://www.redlineoil.com/product.aspx?pid=40&pcid=4

75W90

http://www.redlineoil.com/product.aspx?pid=133&pcid=4

 

I used Redline Oils for my dif changes. I used 75W85 in the front and rear and 75W90 in the transfer case just as Toyota recommends. Not sure about any benefits you were asking about, I just wanted good quality synthetics and used the recommended weights.

 

75w85 was spec for the front so they can squeeze every single mpg for the sticker. the difference between 75w85 and 75w90 is not big at all, and that 75w90 obviously will shear down over time to 85 anyway, now when 85 shears, will you still have the most protection? nope.
imo go 75w90 all around, less hassle of mixing hoses/pumps/bottles and better protection...even though like i said difference between the two is so minimal it's not worth overthinking it.

 

Thanks. That is exacty the reason I thought the 75W85 was specified. I am going to use the 75W90.

 

Someone asked what the differance in using RedLine oil would be. I was getting ready to rebuild the 5-speed in my '72 Datsun 510, as the 2nd gear sychros were completely shot. Someone suggested I try some RedLine gearbox lube first. I am completely blown away, by this product as now there is no problem shifting into second gear (or even downshifting) at all. I then changed the tranny-fluid to RedLine in all of my other cars too. I'm sold. If it helps old cars, think what it will do for our Tacos.

 

Wheres a good place to buy this stuff? Online or do most autostores carry it?

 

Most performance shops or truck accessory places that order from Keystone distributors should be able to get some for you. Most auto stores don't carry it. At least not the stores around me. Good Luck

 

'72 510=WIN!
I had an all-original '72 240Z and loved it.