Oil Change for 2014 360 wet sump

[CBuff]

My 2023 420r Duratec is specd with 5w50 motul 8100 (although I used Mobil one 5w50 for my first change ). 

[MV8]

I'm not surprised it has graduated to the only recommendation. The engine mfg specifies (usually whatever weight was used for certification). Some engines can tolerate other oil weights but there is a best weight for conditions. 

[Croc]

19 hours ago, MV8 said:

Croc, was there a reason/issue for making the recommendation to correct something? it would be interesting to hear how a person at Cosworth (or anywhere) can support that over using the correct viscosity.

 

When I first was told that weight by Jon at RMC, I was surprised.  It comes down to what they think works with that level of tune (runs rich), the way the dry sump operates, and prevailing oil temps the engine expects to run, which are fearsomely high on track with a CSR260.  My logic would have led me to a different spec but I will trust Cosworth in this instance.  It must work as there are a lot of long lived CSRs still running their original engines, including me.  However, I am extremely paranoid about correct oil levels.