Originally Posted By: seekingbuddha
This thread came at a good time for me, so i will add my findings.....The efficiency rating on the WIX/XP (Napa Premium) seem to be not good, from what i see today using google search. Napa premium costs $11.25 from NAPA store local. Fram Ultra is the cheapest at $7.62 for my car at amazon. Mobil Extended is $10 at amazon, but it is not pure synthetic media. Royal purple costs $12.7 for honda civic at amazon and my search reveals good efficiency rating for it, similar to Amsoil (which is the most expensive at $20 at their website).
UPDATE (and answer to Paul Bell's question to me):
I spent time, calling some companies regarding air filters and checking into effiency related articles for air/oil filters. A correction to my previous post is needed based on Multi-pass test efficiency (the standard among all), quoted in a pdf doc i found at Mobil website for extended performance. Even though it is a blend of synthetic + cellulose, it seems to have higher efficiency of 99.6%, compared to 99% of Royal Purple. Both are measured at 25 microns but Amsoil is the best with 98.7% efficiency quoted at 20 microns. I need to update my above post, with the price on Amsoil, to include shipping (which i can avoid for other products, through amazon). For 2008 honda civic Amsoil Ea is $27 including shipping. It is $30 for 1996 Nissan Altima (25k mile filter). If you order multiple products from Amsoil website (or become a preferred customer for $10), the shipping/price comes down a bit.
Paul - yes, the Napa filter is the Premium version for 2008 Honda Civic. I searched Donaldson website to find passenger car filters; their website is is not easy to navigate/search for "transportation" applications. If anyone finds more details on Donaldson please post. BTW, does Fleetguard make passenger car oil+air filters ? They got lot of good info on their website regarding filteration, and have high tech products.
I ruled out Purolator PureOne, due to recent reports of tears. From what i hear, Purolator is aware of this problem, and they are working on it. The company seems to be in chaos due to recent acquisition, including the telephone operator at front end. But, their customer service is still great, and i will be considering PureOne next year, due to their price point.
So, for this time around, i am going with Mobil Extended due to their efficiency + price combination is the best among the oil filters referenced in this thread; and my last UOA reveals that i can easily take it to 15,000+ miles, as guaranteed. I do like Royal Purple for their construction, but i am not sure why their efficiency is lower than Mobil, even though they seem to use purely synthetic material. I will post my findings on air filters at a later date, in another thread.