This is not an official Toyota comparison - this is just something we cooked up in the Olathe Toyota parts department. Please see the notes section for more details.
As every backyard mechanic knows, motor oil is the lifeblood of the modern internal combustion engine. If you want your engine to run a long, long time, the oil you use should perform well in all conditions and circumstances. To that end, many Tundra owners run full synthetic oil in their trucks because it performs well in a very wide range of temperatures, doesn't oxidize as quickly as "natural" oil, and doesn't break down as easily during heavy use. On 2010 and newer Tundras, Toyota recommends synthetic oil over natural oil, and many dealers suggest owners use synthetic as well.
However, what about the filter? How can a Tundra owner know if one filter is any better than another? We've tried to answer that question by comparing five different Tundra oil filters using the following criteria:
- Filter medium size and total surface area
- Filter medium thickness and density
- Filter medium microscopic analysis
- General observations about production quality, country of origin, etc.
While we hope you find the criteria above useful and interesting, the following must be noted: No filter comparison is complete without filter medium performance data. Unfortunately, determining the performance of a specific medium is nearly impossible without expensive testing equipment, and even then certain assumptions must be made (more about that below).
Overall, we think the comparison data we've pulled together will shine some light on the different filters and, at the very least, give any truck owner who changes their own oil some good oil filter background info.
Oil Filter Design 101
Before we get to the comparison data, we need to discuss a few aspects of oil filter design. First, it's important to understand that it takes pressure to drive oil through a filter. If, for example, we're driving down the highway, our oil system might be operating near 40psi. In order to filter that oil, we need to use some of that 40lbs of pressure to push our oil through the filter material (aka filter medium).
As you can imagine, pushing oil through a filter is a lot like pouring water through a coffee filter: if you try to pour too much oil too quickly, the filter can't keep up. When oil can't flow through the filter, it's driven through a bypass valve instead, the thinking being that unfiltered oil is better for your engine than no oil at all. On most vehicles, the bypass valve is activated when:
- The engine oil is too viscous to flow through the filter quickly, typically at vehicle start-up when oil is cold
- The oil filter has become so dirty that oil can no longer flow through the filter medium (obviously, this is bad)
On the Tundra, Toyota engineers decided they would use a "cartridge" type filter on the 4.6L and 5.7L V8's rather than a more traditional can filter. This means that the bypass valve is not part of the filter assembly you buy. While it's only a guess (and an unofficial guess at that), Toyota has probably gone with this type of design because, as you can read in our Tacoma oil filter comparison, some of the after-market oil filter bypass valves are terrible in terms of quality - even non-functional. Considering the tight tolerances on Toyota's 4.6L and 5.7L V8 engine family, a non-functional bypass valve that resulted in restricted oil flow could have dire consequences.
In addition to knowing about the bypass valve, it's also important to know that there are trade-offs in oil filter medium design. For example, you can use a filter medium that can screen out 99% of the particles as small as 2 microns, but what happens when the engine is running at full throttle? A filter medium that's too restrictive won't filter any oil at all, because the oil will just flow right past the restrictive, slow-flowing filter and instead go through the bypass valve.
On the other hand, it's been shown that particles as small as 2 microns contribute to engine wear. What's an oil filter designer to do? If they use a material that's too restrictive, the oil just bypasses the filter. Obviously, they must compromise between filtration and flow rate.
Our Oil Filter Comparison Method
Our comparison method seeks to relatively determine how well oil can flow through a particular medium based on:
- the surface area of the filter medium - more surface area means better flow
- the density of the filter medium relative to the OEM filter
- the microscopic view of the filter mediums, specifically looking for distribution, consistency, and void space
Additionally, we'll look at some miscellaneous other factors that indicate manufacturing quality, and of course price.
There are a couple of problems with our comparison. First, the scale we used to measure weight isn't terribly accurate. Therefore, our density figures are estimates only - they're useful relative to one another, but you wouldn't want to use our density numbers for your own analysis. Second, two of our filters were identical in almost all respects, with very slight differences in dimensions. This wasn't intentional - we bought what we thought were five different brands.
Again, it should be noted that our comparison is both relative and incomplete. Without testing the performance of each filter medium in a wide range of pressures, with and without contaminants, and also at different temperatures, it's hard to know which filter is truly best. The average vehicle can generate oil pressures as high as 70psi and as low as 10psi, operate in temperatures from the arctic to the desert, and generate all kinds of contaminants - which filter does the best in all the possible scenarios? Obviously, that kind of testing is not an easy thing to do, and certainly beyond the scope of this effort.
Finally, you'll note that we're using the Toyota OEM standard filter as our benchmark. To be clear, this isn't because we're in the business of selling Toyota oil filters - it's because we believe Toyota wouldn't sell a filter that didn't meet their minimum standards and strict production system guidelines. While that may be an incorrect assumption, we think it's very reasonable.
Click on each photo above to see the full-size versions of the 40x magnification (left) and the 150x magnification (right)
While it's hard to tell a lot by looking, the Fram filter medium is clearly denser and "flatter" than the others. Additionally, the MicroGard/Standard Fram filter material seems slightly denser than the Wix and OEM filter mediums, with less void space. Of the four, the Wix filter medium seems to have the greatest amount of void space (important for flow) while also having a large number of filter threads. It's likely that oil flows through the Wix filter medium faster than all the others.
Filter Comparison Data
In no particular order -
|Price Paid||Country of Manufacture||Instructions||Cartridge End Cap Material||Dry Weight (grams)||Outer Diameter (mm)||Inner Diameter (mm)||Length (mm)||No. of Pleats||Total Filter Area (calculated, cm2)||Thickness of Filter Material (mm)||Density of Filter Material (calculated, g/cm3)|
|OEM Toyota Filter (01452-YZZA4)||$4.33||Thailand||Schematics printed on box||Small clear plastic cap||45||69.35||28.25||111.35||43||1967.89||1.00||0.19|
|MicroGard (MGL10295)||$6.59||South Korea||Printed insert, great quality||Large, 4.7mm thick clear plastic cap||61||67.60||28.02||106.82||45||1902.57||1.12||0.18|
|Fram ExtraGuard (CH10295)||$9.49||China||Printed insert, pictures are dark||Large, 3mm thick black plastic cap||61||65.19||28.35||108.89||44||1765.06||0.88||0.25|
|Fram Standard (CH10295)||$6.44||South Korea||Printed insert, great quality||Large, 4.7mm thick clear plastic cap||61||67.85||28.07||106.32||45||1903.23||1.08||0.19|
|WIX (57041)||$6.99||Poland||Printed insert, schematics similar to OEM||Small clear plastic cap, slightly larger than OEM||40||68.60||29.07||113.40||43||1927.56||0.98||0.15|
1) The Standard Toyota OEM Filter
General Observations: First, this filter is bigger around than all the other filters we looked at. As a result, it has a strong advantage over the competition. A bigger cartridge diameter means a bigger surface area, which in turn means that oil will flow through this filter faster than smaller filters (all things being equal).
Next, the filter material used in the OEM filter looks and feels like the filter material used by Wix and on the standard MicroGard/Fram filters. When we look at the OEM filter material under the microscope, we see that for the most part, the OEM material matches the material from Wix and MicrogGard/Fram. Yet Toyota's filter material is thinner than the MicroGard/Fram filter material, so it should flow faster.
Flaws We Found: The biggest flaw in this filter is that, because there's a glued seam in the filter paper, two pleats that should be separated are instead glued together. This reduces the effective filtering area. The other flaws we found: the pleats aren't completely even in terms of spacing, and Toyota's instructions were the worst of the bunch. They're functional, but not exactly clear.
Verdict: For the price, it's hard to beat the OEM filter. It offered the greatest filter area, and the density and microscopic appearance is consistent with filters from Wix and Fram, yet it's the least expensive option.
2) The MicroGard Filter And The Standard Fram Filter (One In The Same)
General Observations: First, it should be noted that the only difference between a MicroGard filter (O'Reilly brand) and the standard old Fram filter is printed lettering on the end caps - and the box they come it. That's it. We cut both of them up and measured just to be sure, but they are the same.
Next, the design of the end caps on this filter result in perfect pleat spacing. While it's unknown if perfect pleat spacing makes any difference in performance, it seems logical to conclude that perfect spacing could help. Fram/MicroGard should also be congratulated for offering the best set of instructions of any of the filters we looked at. While instructions aren't a big deal, they show a commitment to customer service. These filters also come with a nice little reusable zip-top bag. Again, a small thing, but a nice touch.
The filter media thickness on these is 10% higher than the OEM filter, and while the microscopic view shows that the Fram/MicroGard medium is very similar to the Wix medium, the density data suggests that the Fram/MicroGard filter media is about the same as the OEM filter media. What does all this mean? Probably that the Fram/MicroGard filter flows a little more slowly than the OEM filter, and also perhaps that the Fram/MicroGard filter catches more contaminants.
Flaws We Found: The biggest flaw in this filter is the end caps. While they result in great spacing - and look cool - they take up a lot of space that could be used for filter material.
Verdict: The microscope shows that the filter medium looks a heck of a lot like the Wix filter medium, yet the density data shows that the Fram/MicroGard filter medium is most similar to the OEM filter. Based on the overall quality, these filters are definitely acceptable. If you can get a great deal, they're probably worth a look.
3) The Fram ExtraGuard Filter
General Observations: For the highest cost filter we tested, there's not much positive to say. The pleats were mostly even, but the seam pleat wasn't quite full size (as a result, our calculated total area is a little generous on this filter). The instructions were just OK, with pictures that were difficult to make out.
Fram's website says that their ExtraGaurd filters are 95% efficient for particles larger than 20 microns. However, this rating applies to three specific Fram filters - the PH8A, 3387A and 6607. While it's unlikely that Fram would build these three filters much differently than they would build any other filter, it's certainly possible that the Tundra filter doesn't meet that same standard. Still, this rating is comparable to the stated rating of the Wix filter below.
Flaws We Found: First, we have the fact that this is the smallest filter in terms of the surface area AND it has the densest filter medium. This means that the Fram ExtraGuard filter is going to be more restrictive than any of the other filters we've evaluated. While this doesn't necessarily mean that the Fram ExtraGuard will restrict oil flow and trigger the opening of the bypass valve, it's not exactly encouraging that the OEM filter is considerably larger (10% more surface area) and likely much more free-flowing (a quick glance at the microscopic comparison shows as much, not to mention our density figures). Of course, the ExtraGuard medium is also thinner, so perhaps the differences aren't as extreme as they appear - but the microscope definitely lends credence to the idea that this filter is more restrictive than the OEM filter.
Next, the manufacturing seems to lack consistency. The two end caps, for example, were different in thickness compared to one another - about .2 mm off. They were also inconsistent in thickness from one point to another on the same cap. In truth, this means very little in terms of performance...but poor manufacturing tolerances on end caps aren't a sign of rigorous quality.
Finally, there were countless loose fibers on the surface of the filter medium, including a long strand of plastic or glue that looked a lot like a human hair (but wasn't). Since these fibers will probably never make it past the filter, this isn't a big deal - but what if the inside of the filter has the same loose material? That's not something we want to take a trip through the oil system.
Verdict: Fram always seems to get the short end of the stick in these oil filter comparisons, but based on everything we've seen, the standard, less expensive Fram filter seems like a much better option. While it could be that the ExtraGuard really does an excellent job of filtering out small particles (that's the claim on the box), it could also be the most restrictive filter here. As we've said before, what good is a high performance filter medium if oil is sneaking past it via the bypass valve?
4) The Wix filter
General Observations: In other oil filter comparisons (see our notes below), the Wix brand usually comes out near the top. While the Wix filter wasn't quite as big as the OEM Toyota filter (in terms of overall size and surface area), the difference was very slight. Add in the fact that the Wix filter medium is less dense than any of the other filters we tested, and that the microscopic view shows a very consistent filter material, there's a lot to like here. The Wix filter just might be the least restrictive of the bunch, despite that it has a smaller surface area than the OEM filter.
What's more, Wix publishes the beta ratio (learn about beta ratios here) of this filter on their website. According to Wix, this filter (which again is less dense than the OEM filter) captures 50% of particles larger than 21 microns and 95% of particles larger than 44 microns (nominal size). For comparison's sake, Fram's website says that their Extra Guard filters are 95% efficient at 20 microns or larger...however, that rating is NOT for a Tundra filter (it's the rating for three standard sizes that Fram tested). At best, the Extra Guard and Wix filters perform similarly, yet the Wix filter costs less and has more surface area.
Flaws We Found: Just like the OEM filter, the pleats are a bit uneven in terms of spacing and the Wix filter also has a "superpleat" - two different pleats glued together. -Nothing to report otherwise.
Verdict: If we assume that Toyota engineers went with a cartridge type filter for the Tundra because they wanted to make sure that the bypass valve operated exactly as intended, it's safe to assume these engineers did so because they were concerned about oil flow. As we've noted above, many after-market oil filters have incredibly poorly designed bypass valves, which means oil flow can be restricted by the filter, which means the engine doesn't get the oil it needs at start-up or while on the heavy throttle. Toyota avoids this problem if they take the after-market out of the bypass valve picture.
Therefore, it seems logical that a high flowing filter is the best choice. While it's hard to know for sure if the Wix filter flows the best, it seems likely. Of course, the Wix filter is also more expensive than the OEM filter (almost 50% more expensive), and that's based on a sale price. Is the Wix worth 50% more money than the OEM filter?
We also have to wonder if the Wix is too free-flowing - perhaps not dense or thick enough to filter out particulates. Hard to say with the data we have.
Based on all the data and observation, it seems like the Wix is probably the best flowing filter and that the OEM Toyota filter is probably the best value. In most respects, the Wix and the OEM Toyota filter match up, so it's not really clear that one is any better than the other. What's more, the Fram/MicroGard filters would seem to be close to the Wix and OEM filters in terms of performance.
Unfortunately, despite the feel-good fact that we liked the Wix, OEM, and standard Fram or MicroGard filters, it's hard to recommend the Fram ExtraGuard filter. The inconsistent manufacturing and loose surface particles, combined with the smallest surface area and highest density, indicate a bad match for an engine that likely needs a free-flowing oil supply.
Ultimately, this data shows that you must give the OEM Toyota oil filter serious consideration. It just may be that the Toyota filter offers the best combination of filtration performance and flow rate, and even if that's not the case, there's not enough difference from one filter to another to justify a higher cost. For these reasons, it seems like the OEM filter is a very smart choice.
1. This isn't an official Toyota comparison - this is something we did here at Olathe Toyota Parts. We hired Jason Lancaster, editor of TundraHeadquarters.com, to conduct this comparison, but we didn't pay him to generate a specific result. Jason acted completely independently and in good faith. If you have questions about methodology, etc., please contact Jason directly.
2. For more oil filter comparisons and info, check out the following:
- http://www.youtube.com/watch?v=JSC9KZGDRDk - NOTE: This video is unabashedly pro-Fram, so you might want to discount some of the info accordingly. However, love Fram filters or hate them, it's a great video explanation of how an oil filter works.
- http://www.aftermarketsuppliers.org/Councils/Filter-Manufacturers-Council/TSBs-2/English/02-2.pdf - A nice basic explanation of oil filter filtration media from the aftermarket filter manufacturer's council
- http://www.aftermarketsuppliers.org/Councils/Filter-Manufacturers-Council/TSBs-2/English/89-5R3.pdf - Another good explanation of micron ratings from the oil filter manufacturer's council
3. Please share this filter comparison on your favorite forum, your blog, on Facebook, etc. If people like this comparison, we can do more!