# Febi Bilstein 75w GL4 gear oil...synthetic or semi-synthetic?



## cmathie86 (Apr 1, 2015)

Hi wondering if anyone can tell me if this gear oil is a full synthetic or semi-synthetic? All it says is mineral base...but its approved for 2003 vw jetta 2.0 and also it only says 75w GL4...why doesnt it say 75w90 or 75w80 which weight would it be?? http://www.partsgeek.com/1lj6hxc-me...sGeek+Nextag&fp=pp&utm_term=Mercedes+Gear+Oil


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## Butcher (Jan 31, 2001)

Mineral base oil is not synthetic or even semi synthetic. It says 75w because that the specs it is.

Everything on the internet is not the truth. I would inquire with the company about your question. Nobody here can give you a real answer.


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## CustomBuilder (Mar 7, 2017)

*If U Look Up - Old Farm Equipment*

U - will Find that they also use - Straight Mineral Oil 75W in all those Hydraulics of which some Cost 30K-55K just for the Hydraulics . . 

Now Smoke that !

List the VW DSG - product Data Sheet for the hydraulic Mineral Oil 75W VW uses - it has to be Supplied as do the Hazards warnings . . 

Then Go Shopping . . :biggrinsanta:

To Hit the Mark You'll need - hydraulic oils should resist varnish formation, which can result in sticking servo-valves. 
Also thermal stability testing to validate the anti-wear performance and thermal stability of a fluid. 
Anti Wear Properties . . with Extended Life Time . 

This is what Happens : 

Oxidation rates for hydraulic oil can double for every 10° C increase in operating temperature. Hydraulic oils will still operate at temperatures above 180° F; however, the oxidation rate will have Accelerated, Decreasing the Life of the Oil. As hydraulic oil becomes oxidized and Thermally Degraded, varnish particles may form.


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