What is the difference between engine oil and final transmission oil? Can I use the same oil for both?

[TaigaRU]

I have reached 1000km on my Yamaha NMAX and I need to change engine oil. It is also recommended that I change my final transmission oil.

As it says on my owners manual:

Engine oil SAE viscosity grades: 10W-40

Final transmission oil type: Motor oil SAE 10W-40 type SG or higher.

I have bought Castrol Power 1 Racing 10W-40 for my engine oil, but is it ok if I use it for final transmission oil also? If no, what product should I buy? Thanks.

 

[bud]

I wouldn't. Although it's rated the same, the gearbox oil thickness is calculated differently.

[Mississippi Bullfrog]

If the manual is specifying motor oil 10W-40 grade SG and above then the Castrol Racing ought to be fine. It's a good oil. I use it in the Bobber and the gear change is noticeably slicker with ii installed. It is rated as API SL. 

 

Just looking at the manual and it does indeed recommend motor oil for both the engine and final transmission so it should be fine.

Edited May 11, 2022 by Mississippi Bullfrog

[DJP]

I agree with MB above: They're recommending the same oil for both.

[Gerontious]

9 hours ago, DJP said:

I agree with MB above: They're recommending the same oil for both.

 

Which seems odd, but it is after all a CVT scooter with belt drive. so far more forgiving.

[bud]

Looking it up Castrol recommend using a different oil for the gearbox. It's cheaper too.

Castrol MTX 10W-40 is a mineral oil based multigrade motorcycle gear oil. It is suitable for use in two and four-stroke motorcycles with separate manual or automatic transmission with or without wet clutch. We recommend its use wherever a multigrade engine oil is provided by the manufacturer in the transmission area.

[Fozzie]

19 hours ago, TaigaRU said:

I have reached 1000km on my Yamaha NMAX and I need to change engine oil. It is also recommended that I change my final transmission oil.

As it says on my owners manual:

Engine oil SAE viscosity grades: 10W-40

Final transmission oil type: Motor oil SAE 10W-40 type SG or higher.

I have bought Castrol Power 1 Racing 10W-40 for my engine oil, but is it ok if I use it for final transmission oil also? If no, what product should I buy? Thanks.

 

 

Just checked the service manual online, and if your scooter is the NMAX 125, the oil is the same for both engine and transmission. Only 0.15 litres required. 

 

Halfords part synthetic 10W40 oil is SG rated, if you want a cheap alternative in future. The Castrol oil you've gone for is SL I think, which is superior, but if you're on top of your servicing it is likely overkill and a bit costly. 

 

[Mississippi Bullfrog]

3 hours ago, Fozzie said:

 The Castrol oil you've gone for is SL I think, which is superior, but if you're on top of your servicing it is likely overkill and a bit costly. 

 

Yes, but it is a much prettier colour. It is like freshly squeezed cranberry juice.