Problem is that a freer flowing filter only ever gives it's benefits at W.O.T. (even if that)...

Every other part of your driving is at part throttle, so adding a resistance between the air intake and the throttle butterfly does nothing for either performance or economy, except let dust through.

Hi guys, first time here... Agree that the TBN looks pretty whacked... Viscosity retention is good, but the 5W-50 looks like it's turned into a 15W-40 in the time that it was in your engine. Going from a data sheet 17.5 to 16, and thickening up somewhat. The 0W-40 is reputed to throw higher metals, ...