SKF Energy Efficient (E2) deep groove ball bearings

[alsmith]

Has anyone tried these SKF Energy Efficient (E2) deep groove ball bearings in their motor? They claim 30% less losses through friction at the bearing against their standard bearings, probably more when looking at the cheap Chinese bearings fitted as standard in most motors. I know there are other losses in the system, but how difference will this reduction at the bearing have? And what about any downsides?

http://www.skf.com/portal/skf/home/products?lang=en&maincatalogue=1&newlink=1_1_90

 

[alsmith]

It seems only the S3 clearance bearings are in the supply chain so it's no go for these.