your argument is both strange and odd, if the genuine renault filter for the F4R engine was no good then surely every single F4R engine in existence would've gone bang by now?
and FYI the diesel engines use the same oil pump as the F4
No, your argument is a strawman.
The filter will obviously do no harm to the engine in the short term. But if it reduces the oil pressure (actually a measure of oil flow) then logically the amount of oil arriving at the top of the engine will be reduced.
I have measured these filters on a F7R and i know for a fact that the genuine Renault filter (mann 75/3) now supplied for the williams restricts the flow (reduced pressure) compared to the original filter (mann 75/2) that has now been discontinued. After discovering this i wrote to mann and asked about the difference in the filters and they told me that the pore size, by-pass valve release pressure and flow rate are different. They said this is very likely the reason for the pressure changes. They even advised me not to use it (the 75/3).
After this i researched filters with the same or similar spec to the original mann filter and found the champion f136 is a better match. Nearly all the wc lot now use this filter, because it works and gives correct book oil pressure. I have since found another filter that is also more suitable.
The reason renault supply 1 filter for most cars is because of cost saving.
Now i have no idea about oil pressure in the f4r. But i would be willing to bet that the purflux filter restricts the pressure as it does in the f7r.
Using words like 'surely' intimate that you have not investigated this matter and therefore are in no real position to make an informed judgement.
People with low oil pressure and apparent pressure problems have fitted the champion filter to a williams and returned the pressure to the normal range.
