Filter Minders for Dummies

[pgchin]

As a DATAPOINT. I can tell you my 475 HP s60 has never had an issue with the FM. Always in the green and when I pulled apart the 10 year old air filter from the PO it looked brand new with NO water intrusion. I run a "short pipe" with a 45 degree cut facing the road side. I'd have a tendency to agree with David here and speculate that there isn't an issue here with air flow but a true test setup as David described will provide real data to act / react on. I also drive like grandma. Sixty-two most time at about 1500-1600 RPM's. I can also still pull 30-35 on the turbo under load on a cool 60-75 degree morning when the engine is warmed up. Example, route 40 from Tom Johnson's in Marion county heading west into Asheville, NC. Its a pull in the east mountain directory slated at about a 6% accent. I run a STOCK air inlet system and STOCK exhaust / muffler system, no stainless less restricted stuff. DDEC III stock programming. So NOT everyone has an FM issue albeit I'm a 475 HP guy, most others are 500HP.
FWIW, the factory made changes for NO rhyme or reason, as an example, the air inlets on LXI's. Sometimes it was for an engineering change based on dealer feedback (which also could be the case of the LXI inlet), MOST times it's because that's all the parts they had in the bin so they built out what they had. I've said this over the decades, I've talked to them in person at the factory about this very thing. EACH one of these things is custom, built by the same or different guys and gals. They start with a standard set of prints and if a customer custom order required a change to the routing or a part in the print, they'd do it on the fly, it is NOT in the print. I've even seen anomalies in 95's at rallies where the SAME subsystem is wired / set up differently. DIFFERENT people worked the line and buses on different days. They only time they updated the prints is when they brought out a new subsystem. That's why, for example, my factory 95 set of prints I bought at the factory have print dates from 90-95 on them. Some of my subsystems are common with 90's, so I have their prints, subsystems common to 95, new ones, have new prints. I paid 275 bucks for them back in the day and when I saw the different dates on the prints, I was NOT happy!!!! I MADE Bennie and Earl both go back to the computer and pull the print part numbers TWICE EACH and compare them for my build number to confirm the above story about the line builds (that's when they spilled the beans) and to make sure I had the correct print set for my build number.