I know this subject has been beaten to death several times now, and there was even a Pennzoil Q&A on the subject, but i havent read anything about extended drain intervals vs timing chain wear. Is this not a consideration to anyone pushing 10-20k mile oci? Pennzoil and many other oils on the shelf do not reccomend extended drain intervals so it had me thinking perhaps the dispersant additives arent up to the task after 5k miles?
Q&A from Pennzoil:
Q: How much can motor oil really affect the wear on the valve train? Timing chain?
A: For timing chains, in addition to the need for correct wear protection additives and friction modifiers, the oil formulators also watch the dispersants in the oil quite closely. The fear is that without a suitable dispersant, soot and carbon in the oil could collect inside the pins of the chain and create wear or limit movement that would result in the chain's effective length changing. If the chain's effective length changes even slightly, it can be sensed by the ECM and create problems.
Q&A from Pennzoil:
Q: How much can motor oil really affect the wear on the valve train? Timing chain?
A: For timing chains, in addition to the need for correct wear protection additives and friction modifiers, the oil formulators also watch the dispersants in the oil quite closely. The fear is that without a suitable dispersant, soot and carbon in the oil could collect inside the pins of the chain and create wear or limit movement that would result in the chain's effective length changing. If the chain's effective length changes even slightly, it can be sensed by the ECM and create problems.