Am 18.07.2019 um 16:14 schrieb Frank Krygowski:
On Thursday, July 18, 2019 at 5:14:53 AM UTC-4, Rolf Mantel wrote:

Changing the oil bath of my Rohloff first time after some 5 years did
give me a massive speed boost, like pumping up the tires from 20 to 80
psi (I should have changed that oil a lot earlier).

Wow, that's the first time I've heard of that. Was the old oil extremely viscous?

I must admit I asked the bike dealer to do the oil change for me so I
don't know.

I believe Rohloff used to recommend change between "summer" and "winter"
oil but at least once per year in the past. Then they put an "all-year"
oil to market, and I vaguely recall to have read something that at least
in the first year an oil change would be quite important.

On the German bike forums, some people mention that the relevant part
would be more an "oil topup" rather than an "oil change" and the hub
gets louder and loses efficiency when lacking oil.