Will this adapter raise your oil pressure? Maybe/May not. Some people are seeing a 10% increase.
The purpose to use this adapter is to use the Wix 51268 oil filter. You will see in the documents here, the 51268 has almost the same flow as the performance 51515R, and almost the same filtering as the standard 51515 filter. So really the purpose to choose to use this adapter is you can have the filtering quality and flow ability. Generally, performance filters gain the extra flow by reducing the filtering ability.

*51268 WIX max flow rate 18-20, Filtering micron rating 25 (smaller the better)

*51515 WIX max flow rate 7-9, Filtering micron rating 21 (smaller the better)

*51515R WIX max flow rate 28, Filtering micron rating 61 (smaller the better)

**NOTE DESIGN HAS BEEN CHANGED TO BENIFIT FLOW RATE**