A while back, I made an estimate of what the Brand Ranks testing would look like in efficiency terms. At the time, there was one factor that was unresolved because I didn't have the data and couldn't get my head around how it would affect the calculation. That factor was the ratio of test dust used to test fluid. At the time, I limited what I shared to the high efficiency filters because those would be the ones least impacted by calculation differences.
Since then, I've been able to source the missing information and take a deeper read of ISO 4548-12 to better normalize the Brand Ranks numbers. Below you will find adjusted particle counts and efficiency numbers for all the filters Brand Ranks tested.
Since these numbers have been adjusted, it is important to share what I have done and why;
1) Brand Ranks actually followed a lot of the ISO testing and many of their deviations would not be material. But the one big fatal flaw of what they did was only use 2L of fluid. Andrew on the other hand I estimate used 12.5L. This means the particle count results that Brand Ranks presented are overstated by a factor of 6.25.
2) Andrew added test dust at the rate of 2.1g every 5 minutes which is 0.42g every minute. Brand Ranks added test dust at a rate of 0.55g every minute. This difference has been accounted for in the efficiency calculation ie the estimate of Brand Rank's upstream particle count has been adjusted for this factor.
3) Regardless of calculations and normalization, there will be no way of explaining the Purolator Boss performance vs what we know from elsewhere. However, almost all the other results in the table below make sense both in particle counts and efficiency;
4) These efficiency numbers may still be out by several percentage points since there is nothing as good as following the ISO procedure to the letter, but the adjustment to particle counts for a valid reason based on a single difference in decision on test methodology ie 2L fluid instead of 50% of the flow rate / minimum of 6L, brings the particle counts to believable numbers.
Since then, I've been able to source the missing information and take a deeper read of ISO 4548-12 to better normalize the Brand Ranks numbers. Below you will find adjusted particle counts and efficiency numbers for all the filters Brand Ranks tested.
Since these numbers have been adjusted, it is important to share what I have done and why;
1) Brand Ranks actually followed a lot of the ISO testing and many of their deviations would not be material. But the one big fatal flaw of what they did was only use 2L of fluid. Andrew on the other hand I estimate used 12.5L. This means the particle count results that Brand Ranks presented are overstated by a factor of 6.25.
2) Andrew added test dust at the rate of 2.1g every 5 minutes which is 0.42g every minute. Brand Ranks added test dust at a rate of 0.55g every minute. This difference has been accounted for in the efficiency calculation ie the estimate of Brand Rank's upstream particle count has been adjusted for this factor.
3) Regardless of calculations and normalization, there will be no way of explaining the Purolator Boss performance vs what we know from elsewhere. However, almost all the other results in the table below make sense both in particle counts and efficiency;
- The impact of an Extra Guard leaking but still reaching capacity makes much more sense now that the particle count has been reduced by the 6.25 factor. The Brand Ranks provided numbers were contradictory in terms of implied leak rate and capacity being reached.
- The WIX XP and Napa Platinum test similar to where Andrew had the WIX XP. The fact that they were actually better by 10% suggests they were non leakers unlike Andrew's.
- The Napa Gold had a sticky bypass valve and lost 10% efficiency vs the WIX which was identical
- Toyota & Baldwin are shown to be rock catchers as expected
- The Bosch high efficiency filter comes in at 98.9%
Filter | Capacity grams | Particles 21-38 | Particles 38-70 | Particles 70+ | Efficiency % 21-38 |
|---|---|---|---|---|---|
Extra Guard | 4.5 | 250.1 | 32.3 | 16.2 | 70.0% |
Tough Guard | 5.8 | 91.2 | 0.3 | 0.1 | 89.1% |
Fram Ultra | 6.6 | 5.4 | 0.4 | 0.1 | 99.3% |
Fram Endurance | 4.4 | 2.9 | 0.3 | 0.0 | 99.7% |
WIX XP | 8.6 | 129.1 | 1.6 | 0.2 | 84.5% |
Royal Purple | 4.6 | 9.2 | 0.0 | 0.0 | 98.9% |
Napa Platinum | 8.8 | 156.6 | 0.4 | 0.0 | 81.2% |
Purolator Boss | 9 | 5.1 | 0.0 | 0.0 | 99.4% |
Amsoil | 4.4 | 1.1 | 0.0 | 0.0 | 99.9% |
K&N | 4.5 | 42.3 | 0.1 | 0.0 | 94.9% |
Mann | 6.6 | 24.6 | 0.1 | 0.0 | 97.1% |
Mobil 1 | 5.6 | 40.5 | 3.6 | 0.2 | 95.1% |
WIX | 7.3 | 98.8 | 0.4 | 0.0 | 88.1% |
Napa Gold | 7.9 | 176.6 | 14.2 | 0.8 | 78.8% |
STP XL | 4.4 | 64.2 | 0.8 | 0.1 | 92.3% |
Baldwin | 13.2 | 413.3 | 14.8 | 4.4 | 50.4% |
Motorcraft | 7 | 72.1 | 4.8 | 2.4 | 91.3% |
ACDelco | 4.6 | 21.5 | 1.9 | 0.5 | 97.4% |
Toyota | 13.4 | 443.8 | 58.7 | 25.4 | 46.8% |
Bosch Premium | 4.4 | 9 | 0.8 | 0.2 | 98.9% |
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