Gear oil v.s standard engine oil ?

[dole]

My scooter "Honda PCX" mannual says: gear oil, 10W-30, MB, SL which is also the recommended engine oil.

I found motorbike gear oil specs: Motul, 80W-90 GL-5 and Speedmaster, 85W-140, GL-5.

Huge difference by the look of numbers, 10W-30 v.s 80W-90 even 85W-140, and API SL v.s API GL-5.

So,
#1. what is the difference between the performance? Huge difference I guess?
#2. Which one is better for my scooter?

 

[SwampSurvivor]

Gear oil viscosities are different than engine oil.

 

[racer12306]

Totally different additive packages.

I believe the viscosity numbers are based on a different scale. So while the numbers look very different, it's not as dramatic as it appears when you look at the actual viscosity of the fluid instead of the "weight" on the bottle.

 

[HerrStig]

Is there anything more confusing that two different scales with the same name?

 

[Brybo86]

My 95 Yamaha Jog calls for 10w30 in the transmission/gear case. I use 90w gear oil.
Once scooter get up to 100+cc then they start calling for 140w gear oils

 

[Linctex]

Originally Posted By: dole
My scooter "Honda PCX" mannual says: gear oil, 10W-30, MB, SL which is also the recommended engine oil.


Do not use "gear oil"

You must use "Engine oil"

What oil choices are readily available to you in China?

 

[JMJNet]

Gear oil have a very distinct bad/strong smell (at least on my standard).
It has a high sulfur content.
If you leak it, you can smell it from far away.

Regular motor oil has smell but not the same smell.

Sometimes, you can determine the type of oil from smell.
That is all I am saying.

 

[Brybo86]

Xw30 or Xw40 in the engine and the same or gear oil in the rear gearcase , it only takes like 100ml

 

[LoneRanger]

Gear oil has high quantity of extreme pressure additives. Not usually necessary in a motor.

 

[alarmguy]

Originally Posted By: dole
My scooter "Honda PCX" mannual says: gear oil, 10W-30, MB, SL which is also the recommended engine oil.

I found motorbike gear oil specs: Motul, 80W-90 GL-5 and Speedmaster, 85W-140, GL-5.

Huge difference by the look of numbers, 10W-30 v.s 80W-90 even 85W-140, and API SL v.s API GL-5.

So,
#1. what is the difference between the performance? Huge difference I guess?
#2. Which one is better for my scooter?


The better oil to use IS the one the engine maker says you should use. Listen to them, they are pretty smart people.

 

[Shannow]

The MB is "JASO" MB, which is a Japanese wet clutch specification.

If you are using SL engine oil, those which are friction modified (e.g. a typical ILSAC spec) will be detrimental to the operation of the clutch.

 

[dole]

Well, if I can't use the gear oil, I may just use the Mobil or Shell 0w-40 for the transmission.

 

[dole]

Thank you. It is very helpful information.

 

[MolaKule]

Originally Posted By: LoneRanger
Gear oil has high quantity of extreme pressure additives. Not usually necessary in a motor.

And usually destructive when gear oil is used in an engine.

 

[BrocLuno]

If there is a tractor shop near you, go look for oils that have dual ratings. Here in the USA, we have many oils that are used in heavy equipment in shared sump applications (both engine and transmission). Those are the oils I'd be buying. One to do both jobs

EX: http://www.allisontransmission.com/parts-service/approved-fluids/off-highway-fluids