Today’s question was sent by Bastiaan:

Hello,
I have a question for my car Honda s2000. It has a torsen rear differential, rear wheel drive.
There is much discussion online about which oil to use.

Options are: 75w90, 80w90, 75w140. Some can be found in mineral and some in synthetic.

I dont know if you are just a company that produces torsen differentials, or if you guys are THE torsen manufacturer and original.

Anyway, can you recoomend me between the different oils for my car? It’s a daily driver, sporty drive style, not tracking.

Please let me know what would be the best option.

thanks much appreciated!

kind regards
 Bastiaan

Bastiaan,

Thank you for contacting Torsen.  Note that we are Torsen with a capital “T”; Torsen is our brand name and our trademark.  No other companies can use the name “Torsen” legally.

With regards to you lubrication question – the short answer is it doesn’t make much difference to the differential.  Ultimately, it’s a question for the axle manufacturer.  What I mean is, the differential operates as just one component in a larger system, a system that shares lubricant.  The axle assembly that contains the differential also contains other significant components to which proper lubrication is equally (or more) important.  Helical gear differentials like the Torsen that came in your car can actually operate in wide range of fluids and are not particularly fussy about it, so long as the lubricant is of a good quality.  They will operate just fine in all of the oil weights that you’ve mentioned.  On the other hand, the ring gear and the pinion gear that drives it are extremely fussy about correct lubrication.  So are the bearings and oil seals, though most people don’t consider them.

A lot of people ask the same basic question – what lube does the Torsen need?  Basically, I have to point out that this is not the correct question to ask, for the reasons mentioned before.  What you need to ask is “what oil does my ring & pinion gearing need?”  That is what you should be concerned with, as the differential itself doesn’t really care.  You’ll need to ask the gear manufacturer that.  If you are using the production ring & pinion gears, that information should be included in your owner’s manual, or available from the dealer.

Regards,

JTEKT Torsen North America, Inc.