85-90 vs 80-90 diff oil for Mercedes?

[Rev_Tim]

I have a 1996 Mercedes C220 and I want to change the differential oil. I was told the OEM specs are for 85-90 and, since there doesn't seem to be a synthetic in that viscosity, I called a dealership parts department to see if they had an OEM synthetic. The parts guy said he didn't know the viscosity or if it was dino or syn.. all he had in his database was it was OEM differential oil. nothing more.

The fella at the parts store said it wasn't a good idea to mess with the viscosity when it comes to the rear end so, I come to where I know I will get the best info... Good ol' Bob.

What say you? Should I just buy the OEM oil at $20 a quart or is there a recommended top grade syn oil I can use? Do I need to stick with the 85-90 spec?

PS: 62K on the car. Owned since new.

Thanks

 

[Quattro Pete]

You might want to check on some dedicated MB forum to see what aftermarket fluids people are using in this car.

My guess is that any good GL5 oil will probably work.

If you want synthetic, AutohausAZ.com is recommending LubroMoly (LiquiMoly) 75w-90 for your car. It's about $13.50/liter and you'll need about 1.5 liters I'm guessing. I actually just ordered some of it for my 530i.

 

[Oldwolf]

I put Mobil 1 75W90 in my differential.

 

[Captain_Klink]

Reverend, the 85-90 is based on you going down the Autobahn at 150 mph for hours on a regular basis. for driving in North America, ANY synthetic or semi synthetic 75 90 will do the job nicely.

 

[mechtech2]

The 80-90 or 75-90 full synth will be an improvement.
How about seeing what Amsoil has to offer?
You don't change your diff fluid often - get a premium type.
See if you have a limited slip in there - this can be important when selecting a fluid.

 

[Rev_Tim]

Good to know... interestingly, I lived in the EU for 3 years and had a 190 C MBZ there. I was keeping up with traffic on the German Autobahn at 160 kph one day... feeling pretty good about myself when a convoy of 4 black Audi 4's and a Ferrari blew by me like I was standing still. They had to be going around 150 MPH.

Also, of note, I called the Mercedes customer support and they couldn't tell me if the OEM was synthetic either.. or what the viscosity was for my year. They did say that they do not recommend that I EVER change my diff oil. Just top off if necessary. I found that interesting to say the least.

PS: I do not have a limited slip differential... sadly.

Thanks for the input.

 

[Kestas]

I've wasted a lot of time conversing in the Mercedes forums. Concensus is that people use synthetic (Mobil 1) 75W-90 in place of the regular 85W-90 specified oil. The price premium for 1.5 liters of synthetic is negligible and worth the extra protection.