The Carquest Premium seem to be one of the best filter choices these days, so I did a pretty in depth look at Carquest's various offerings and though I'd share. Efficiency has been a common question brought up here, and I did my best to organize the contradictory information that is available.
MODELS
To start, Carquest filters come in three main types: the RFI Red Standard, the CFI Blue Premium, and the Heavy Duty. One common size that is available in all three variants is the Standard R85516 / Premium 85516 / Heavy Duty 85516HD. Whip City Wrencher has done a video comparison of the three
here.
MANUFACTURER AND COUNTRY OF ORIGIN
The Red/Blue were once made by Affinia/Wix, then Fram/Champion, then Mann-Humel/Purolator from what I can tell. These days they are made by Premium Guard, which seems to have done a lot for their quality. Country of origin for the PG made filters is primarily China and Vietnam with similar quality for each, but maybe a small advantage to Vietnam-sourced. There's also been mention of some made in India, though I haven't seen that myself.
The Heavy Duty filters are from Hastings/Baldwin, and for many years have been made in the USA. Parker Hannifin acquired Baldwin in 2017 and it seems like more HDs might be being made in Mexico, though I'm not sure about that, or if the two are related.
EFFICIENCY
Carquest shows efficiency ratings of
96% @ 20 microns for the Standard and
99% @ 30 microns for the Premium. I believe these are outdated documents relevant to a previous manufacturer though. The first document goes back to at least August 2016. The second document is more complicated. In September 2015 it was advertising an improvement in efficiency from 96.6% @ 20 microns to 99.5% @ 20 microns. By July 2017 it was updated it its current version, which also shows the Premium as having a nitrile gasket, whereas current versions of the filter should have a silicone gasket.
Relatively recent documents from CQ/AAP show
95.1% @ 20 microns for the Standard and
99.5% @ 20 microns for the Premium. These latter ratings are also the ones found on the AAP product pages. The document for the Premium filter shows the correct silicone gasket.
In CQ's filter database, the former rating for the Premium is most common, as shown
here, but the latter shows up as well, as shown
here.
Complicating the efficiency question even more is the ratings for the associated Premium Guard filters. The PG195 and the PG195EX seem to be the Premium Guard filters corresponding to the Carquest Standard R85516 and Premium 85516. The PG195 and R85516 seem almost identical, but the PG195 is advertised with the
96% @ 20 micron rating. The PG195EX looks very similar to the 85516, but has a
99% @ 25 micron rating that doesn't match the others ratings seen.
Here's all that in a table:
| Model/Source | Old CQ | New CQ/AAP | PG |
| Standard | 96% @ 20 µm | 95.1% @ 20 µm | 96% @ 20 µm |
| Premium | 99% @ 30 µm | 99.5% @ 20 µm | 99% @ 25 µm |
Efficiency data for the HD versions is difficult to find, and I expect it to be more variable among different sizes of filters. Carquest's filter finder tool shows 28 µm for the 85516HD, but lacks any information about efficiency at that size. The Baldwin cross reference for that filter is the B243 which has a rating of
12 µm nominal / 30 µm absolute. I assume the associated percentages are 50% / 98.7%. This would make it less efficient than the Standard and Premium CQ filters. WCW's video has magnified images of each filters' media though, and visually it seems probable that the Standard is the least efficient.
The older associated Hastings model (LF134) didn't reveal any further efficiency information.
Interestingly, Baldwin offers two similar filters (B7511 and B2-HPG) with a 9.8 µm nominal / 27 µm absolute rating.
CONSTRUCTION
- Gasket
- Nitrile for Standard/Heavy Duty, Silicone for Premium. Most seem to be lathe cut, but some are molded P-style.
- ADBV
- Nitrile for Standard/Heavy Duty, Silicone for Premium.
- Media
- Cellulose for Standard, blended synthetic/cellulose for Premium, unknown for Heavy Duty.
- Metal seam for Standard/Premium, glued seam for Heavy Duty.
- Surface area is similar for the three models.
- Core
- Steel core with holes for Standard/Premium and louvers for Heavy Duty.
- End Caps
- Bypass Spring
That's about it. On a personal note, I'm happy with the Carquest Premium as my new go-to filter. My biggest concern is trying to deconflict those various efficiency values so that they can better be compared to competitors. Regarding competitors, the Baldwin B7511 was an interesting find. It doesn't seem like there's a lot of information available about it, but it seems worth looking into.
