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.

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[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

[HIFI]

Multi-viscosity is definitely better. If you can get this go for it.

However, it doesn't mean fixed viscosity oils can't be used. In fact, I wouldn't mind using fixed viscosity type as long as the vehicle is use in the Philippines.

This is just my opinion, being a oil distributor (for the 3 family generations).

[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.

[HIFI]

Touche!

Depending on front wheel or rear wheel drives, gearbox and differentials may have different gear oil specs.

Pero, hindi ganun kalakas ang oil additives to "corrode" the gears. Worst case, perhaps yung mga ibang non-metal parts and seals. Then, again I've never seen a gearbox or differential corrode. Tagas, marami na.

Before we stray further sa topic.

Revenant, go for what your dealer recommends. Refer to the manual if you not sure. Don't listen to me, as I don't make any gurantees. I was just trying to push M2's buttons on the topic. Naghahanap lang ako ng sunog....hehehe.

[mazdamazda]

Hmmm... ok ok... I think you've convinced me for the use of a straight SAE 90 for Philippine road conditions. :D

But I'm still sticking with the multi-viscosity for my transmission. :D