I had to mail order this Carquest Premium 85515 since we don’t have advance auto parts where I live. I opened this CQP up to compare it to an STP S8axl filter which is for the same application.
Carquest says product of Vietnam, STP was China.
Silicone gasket; STP on left, Carquest on right. They measured the same at ~5.5mm when first taken apart but the STP seems to have expanded a little bit after being removed from the baseplate a month ago.
Orange Carquest Anti Drainback valve instead of red STP.
Carquest Premium had a slightly lighter baseplate (170 vs 195g for STP) but CQP had one extra groove for threads. CQP is in the bottom here.
Coil springs, CQP on right, bigger spring with fewer windings.
The CQP seemed to have a thicker can at 1.3mm vs about 0.8 for the STP.
Metal crimped seam for both but CQP had less sloppy glue than the STP.
10% more media area for the CQP at 312 sq in vs 285 sq in for STP. Media was a slightly brighter color for the CQP but width and thickness seemed the same.
CQP bottom, STP top, they were both about 3.65” wide.
Anti drainback valve seemed about the same between the two. I used a trigger pull gauge with a 9mm bullet on the valve and the CQP did seem to open slightly easier, about 2 lbs vs 4 lbs but that’s not a very consistent test. Cores looked about the same with the shinier one to the left below being the CQP.
These differences are probably inconsequential but the CQP’s greater media area are probably the main reason I’d prefer it. It’d be interesting to know if the media material is exactly the same.
I would be considering a CarQuest EP but it doesn't seem like they make one for this application yet. I think the higher flow they advertise for the EP might reduce the liklihood of bypass events (usually have to go full throttle while the oil is only 100 deg F or so, only 2700 rpm max though) even if the filtration efficiency is the same or maybe slightly worse than the CQP.
Carquest says product of Vietnam, STP was China.
Silicone gasket; STP on left, Carquest on right. They measured the same at ~5.5mm when first taken apart but the STP seems to have expanded a little bit after being removed from the baseplate a month ago.
Orange Carquest Anti Drainback valve instead of red STP.
Carquest Premium had a slightly lighter baseplate (170 vs 195g for STP) but CQP had one extra groove for threads. CQP is in the bottom here.
Coil springs, CQP on right, bigger spring with fewer windings.
The CQP seemed to have a thicker can at 1.3mm vs about 0.8 for the STP.
Metal crimped seam for both but CQP had less sloppy glue than the STP.
10% more media area for the CQP at 312 sq in vs 285 sq in for STP. Media was a slightly brighter color for the CQP but width and thickness seemed the same.
CQP bottom, STP top, they were both about 3.65” wide.
Anti drainback valve seemed about the same between the two. I used a trigger pull gauge with a 9mm bullet on the valve and the CQP did seem to open slightly easier, about 2 lbs vs 4 lbs but that’s not a very consistent test. Cores looked about the same with the shinier one to the left below being the CQP.
These differences are probably inconsequential but the CQP’s greater media area are probably the main reason I’d prefer it. It’d be interesting to know if the media material is exactly the same.
I would be considering a CarQuest EP but it doesn't seem like they make one for this application yet. I think the higher flow they advertise for the EP might reduce the liklihood of bypass events (usually have to go full throttle while the oil is only 100 deg F or so, only 2700 rpm max though) even if the filtration efficiency is the same or maybe slightly worse than the CQP.
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