Manual says 75W/85 but only SAE 90 is available

[Revenant]

I'm due for a gear oil change. The manual says 75W/85 is recommended but even the casa only has GL-4 SAE 90. Is it fine to push through with the SAE 90?

Does anyone know of a shop that carries GL-4 75W/85 gear oil?

[mazdamazda]

NOOOOOOOOOOOOO!

SAE90 is thicker than the recommended 75W/85.

Speedyfix carries 75W/85 (or 90) I think for their Royal Purple Gear Oil.

__________________

bigbigcar.com Review: Mercedes-Benz C200 Kompressor Avantgarde

[HIFI]

Bakit hindi puede ang SAE90?

A higher SAE/Viscosity rating is actually preferred in hotter climates.

Hindi naman malaki ang difference.

Most likely, the car in question is an imported version, so the manual states a different rating.

GL-4, is good. I remembered Caltex used to carry a GL-5 (better) gear oil.

[mazdamazda]

That's because the car needs a multi-viscosity gear oil... the transmisssion of most vehicles needs that kind of oil to cope with varying temperatures.

A higher SAE/viscosity rating doesn't also necessarily mean that it'll perform better in hotter climates.

GL-4 and GL-5 is also different, this isn't like motor oil where the preceeding rating is better than the last. If the transmission needs only GL-4, then just use it. If the transmission isn't made to take in GL-5, premature corrosion could occur.

Again, gear oil is different from motor oil.

[HIFI]

Pero, varying temperature ba tayo sa Pinas? I really suspect that this is an imported vehicle.

As for premature corrosion, this is the first time I've heard of it. Corrosion occurs pag may oxidation, it has nothing to do with the GL specs.

BTW, pinapaexecise ko lang ang fingers mo M2....no offense intended.

[sboogie]

mobil has a 80w-90 viscosity and also castrol

[mazdamazda]

Pero, varying temperature ba tayo sa Pinas? I really suspect that this is an imported vehicle.

As for premature corrosion, this is the first time I've heard of it. Corrosion occurs pag may oxidation, it has nothing to do with the GL specs.

BTW, pinapaexecise ko lang ang fingers mo M2....no offense intended.

Ahahaha... none taken.

Yup, our temperature here varies from 16 (Baguio nighttime) to 35 (Metro Manila noontime) - hehe. The operating temperature of your vehicle also varies wildly, from the ambient room temperature when the engine is cold to more than the boiling point of water.

Re: corrosion... that is if you use GL-5 for a GL-4 only gearbox. The GL-5 mixture contains additives that is corrosive to a GL-4 only gearbox. That's because GL-5 is used for high load gears.

It all boils down to what's needed for your machine. The Rav4 needs a multi-viscosity gear oil (GL-4 or GL-5) for the manual transmission and front differential but needs SAE90 GL-5 for the transfer case and rear differential. If there is *no* difference between a multi and single viscosity, why would they bother to specify different gear oil requirements for a single vehicle.