Chrysler and Fiat.

[cb91710]

Sorry to the OP for getting a bit far off the topic but I wanted to ask one more question about oil filters. Rich, we have a 2004 Buick Rainier with the 275hp inline six cylinder. Which filter brand would you use?

Cheers, Todd

Short answer in bold at the end of the post....

As indicated above, any of those three are the best you can buy.
Purolator and Bosch are now the same company. The Bosch filter is basically the same as the basic Purolator.
The Purolator Pure-One is a synthetic media with silicone seals and gasket and is the best available. It is as good, perhaps a little better, than the Mobil-1 at half the price.

Mobil-1 and K&N are both made by Champion Labs (NOT the spark plug people!). While Champion's "normal" filters (AC Delco, WalMart's SuperTech, STP, and a lot of others) are using the E-Core design and are marginally better than Fram, the Mobil-1 and K&N are Champion's premium line. There is no difference between the K&N and Mobil-1 other than the nut welded to the top of the K&N, and the $2-$3 difference in price.

However, around 2005 Champion made a disturbing change to the design of the M1 and K&N filters. Rather than the bypass being the element "floating" on a spring in the cap and opening a bypass "pathway" across the base of the filter, they moved to a plastic button at the top of the element. This means that when the filter goes into bypass, not only is unfiltered oil passed into the engine (which is normal... bad... but normal), that oil now flows across the dirty side of the filter element, possibly carrying additional contamination into the engine.
Of course, the filter medial is not 2D and most of the dirt trapped in the media is truly trapped in the media, there are still contaminants that can be flushed off of the surface.

But that's not enough of a concern for me to strike M1 from my list.
However, the $13 cost compared to the Pure-One's $6 cost has made it my personal go-to filter if available.
If the Pure-One is not available, my #2/3 choices are the Purolator Premium Plus or Bosch (in no particular order, I view them as being identical).
Only due to cost, Mobil-1 is my #4 option if Purolator and Bosch are both unavailable... but considering I keep at least 2 filters for each of my engines in the garage at any given time, I'm not likely to be forced to spend $13 on an M1.

[TheMaxx]

Thanks Rich I think I might switch to purolator filters from now on.