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The Shrinking Oil Filter

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by Tom Evans, Apr 21, 2014.

  1. Tom Evans

    Tom Evans Rockstar

    I got oil and an oil filter today at WalMart for my 2002 Suburban and was surprised at the size of the oil filter. Their book specified a Fram PH3506. It's tiny. I got home and got on line. I see that some of the other vendors are specifying a Fram PH3675 which is bigger than the PH3506, but is still smaller than I remember the factory AC filters being.

    What's happening? Are the oil filter makers trying to get by with smaller filters; hence, smaller amount of filter media; hence, lower manufacturing cost? Or are they trying to get more oil in the crankcase, so you can't tell as readily that you are burning a little oil?

    Curious minds want to know.........
  2. Crawdaddy

    Crawdaddy Epic Member Staff Member 5+ Years 1000 Posts Platinum Contributor

    I would say that it's neither. Manufacturers spec out filter sizes, micron ratings, threading and gasket surfaces, and a myriad of other things. For a 3rd party to change the specs out to try to get away with less would no longer meet the specs. 3rd party manufacturers do often provide multiple part numbers for an application that exceed the performance data, but may be physically larger, but they should never be smaller. Additionally, I don't know of any filter manufacturers that also make/sell oil, so I wouldn't see how they have anything to gain.
  3. Tom Evans

    Tom Evans Rockstar

    I just went to the Fram website. They list both the PH3506 and the PH3675 for my application. There is almost an inch difference in length between the two filters. It also looks like the PH3675 is the preferred oil filter. I guess WalMart is just trying to cut down on the number of filters that they stock. 'Tis a pity, their prices are good.
  4. poncho62

    poncho62 Member 100 Posts

    Engines today run tighter tolerances, thus are supposed to last longer. They also run cleaner (less blowby etc) so the oil should not get as dirty. I suppose this is the theory of the smaller filters.
    That said, this has bothered me too. With synthetic oils, they say you can go longer between oil changes. Even with the synthetics, I still change my oil at 3-4000 miles. Better safe than sorry
  5. bazar01

    bazar01 Member 2 Years 100 Posts

    I think I use AC Delco PF61 on my 2001 Suburban 5.3L. They are twice as long.
    The PF48 I use for the 2011 Silverado 5.3L is half shorter.
  6. Pikey

    Pikey Moderator Staff Member 2 Years ROTM Winner 1000 Posts

    For some reason GM called for the PF 61 on the 2wd 5.3L and the PF 48 on the 4wd equiped 5.3L
  7. poncho62

    poncho62 Member 100 Posts

    I think the shorter filter is needed to clear the front driveshaft
  8. Pikey

    Pikey Moderator Staff Member 2 Years ROTM Winner 1000 Posts

    nope! the longer one fits no problem. the longer one sits about an inch above the skid plate. I know many guys that run the 61 on their 4WD trucks.
  9. bazar01

    bazar01 Member 2 Years 100 Posts

    Nice to know.
    Do they have the same thread pitch?

    If they do, I may need to start using the PF61 on my 2011.
    I really don't like the small filter.
  10. Pikey

    Pikey Moderator Staff Member 2 Years ROTM Winner 1000 Posts

    yes, they are interchangeable.

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