Fuchs 75W-90 or 75W-90 LS?

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Apr 16, 2021
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Guys,

I purchased an oil for the M32 gearbox, Alfa 159. The point is that I ordered a Fuchs Sintopoid 75W-90 LS oil (Limited Slip) instead of a Fuchs Sintopoid 75W-90 Regular oil, as I read in the technical data sheets, the LS is much better.

But a garage informed me that this LS oil, being suitable for differentials, can damage the box, bearings, etc.

From what I read in the technical sheet, LS oil is suitable for everything, having more antifriction additives, wouldn't it be better?

Thanks.
 
What does your owners manual state? The big issue in manual gearboxes is compatability with yellow metals (brass, bronze,etc). Some chemicals don't play nice with copper and can cause issues down the road. If the label statesthat the product is compatible with yellow metals you should be ok.
 
Sintopoid 75w-90LS is listed as GL4 and GL5 so I don't see why it would hurt anything. The limited slip additive is no big deal. FWD cars with certain kinds of LSDs require a limited slip additive and the gearbox and differential share the same oil.
 
What does your owners manual state? The big issue in manual gearboxes is compatability with yellow metals (brass, bronze,etc). Some chemicals don't play nice with copper and can cause issues down the road. If the label statesthat the product is compatible with yellow metals you should be ok.

Owner manual states Tutela 75W-85, but this oil isn't good enough for this M32, low lubrification power and low viscosity, some users used Motul Gear 300 75W-90 with good results. So I checked Fuchs Sintopoid 75W-90 and found that Motul 75W-90 is better until I found Fuchs Sintopoid LS 75W-90 which is better than regular 75W-90.

Sintopoid 75w-90LS is listed as GL4 and GL5 so I don't see why it would hurt anything. The limited slip additive is no big deal. FWD cars with certain kinds of LSDs require a limited slip additive and the gearbox and differential share the same oil.

So there's no problem using this Fuchs LS, as this is GL4 and GL5 both of them?
 
Owner manual states Tutela 75W-85, but this oil isn't good enough for this M32, low lubrification power and low viscosity, some users used Motul Gear 300 75W-90 with good results. So I checked Fuchs Sintopoid 75W-90 and found that Motul 75W-90 is better until I found Fuchs Sintopoid LS 75W-90 which is better than regular 75W-90.



So there's no problem using this Fuchs LS, as this is GL4 and GL5 both of them?
Looks like Tutela is GL4+which is come kind of fancy new school additive package/marketing nonsense. GL4 should be fine. Motul Gear 300 75w90 is also GL4/GL5.
 
Looks like Tutela is GL4+which is come kind of fancy new school additive package/marketing nonsense. GL4 should be fine. Motul Gear 300 75w90 is also GL4/GL5.
Can I use Fuchs Sintopoid 75W-90 LS (Limited Slip), with no worries? It won't hurt anything?

I already bought this oil and was advised to not use it (because garage thinks it's only GL5).

No problem using this LS oil on M32 gearbox of Alfa 159?

Regards!
 
Don't use it if you don't have an LS

LS additives is a big deal

And, LS would not be better.

How do you know something isn't "good enough" for the M32?

What in the technical data sheets told you that LS would be better?
 
Basically this Getrag box requires 70W-75, such as Fuchs Sintofluid FE 75W, Red Line MT-LV etc.

Same box in Chevy Sonic/Cruze

 
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If it has a GL5 rating I would not use it. The combo rating GL4/GL5 just means that they have tried to buffer the additives that make it a GL5 so it presents less of a problem to yellow metals but those additives are still in there. The LS additive wont help you at all so why pay for something and have it take up valuable needed lubrication volume with no benefit.
 
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