Originally Posted By: addyguy
I'll say it again...I do not understand going to all the effort of doing an oil change, and not changing the filter.
You put it up, got out a drain pan...take the extra 2-3 minutes to unscrew the filter and put on another!
JMO....
Not changing the filter would result in the following:
1) less time spent
2) less mess made
3) less cost incurred
4) less material waste in a landfill
5) less chance of leaks (every time you break/install a seal is a "new" potential leak - it if wasn't leaking at first, leaving it alone ensures a continued good seal)
And for what risk? Presuming you have an engine that is not a sludger, and is decently maintained, then there is no risk to an FCI extension. By now, there exists plenty of proof of the excellent capacity in most products. Ford proved it in their SAE study, and my data (over 10,000 UOAs in various applications) shows it to be true as well.
Think of the Ford mod-motors in cars and trucks. Long ago, the O/FCI was 5k miles, with 5w-30 and an FL820. But a few years back, the IOLM showed up and there are some conditions that would allow 10k miles, on essentially the same motor, thinner oil and same filter. We've seen the evidence here; UOAs show no adverse effects. Filter dissections show no cause for panic.
Are you harming an engine by changing a filter with every OCI? No. And if you sleep better at night (insert BOF here), so be it. But neither is harm entering into the engine with an FCI extension. So if the engine wear is assured to be in control either way, then it's OK to look outside that parameter for other decision points.
Hence, ROI. Fewer oil changes and less filters consumed. Less waste, same assured protection.