So I bought a few of the Royal Purple Oil filters for the XK8. My T-bird uses the same filter since the engines are related. I've been stocking up while they are still available. Anywho ... I pulled out a pair from my hoard that I bought in May and opened the box of the one I thought I was going to put on the car. Not so much. Both of them had surface corrosion on the bottom plate under the O-ring. It's the first time I've seen it but I was none too pleased about it. The parts store that orders them for me has a 30 day return policy but since I purchased these over 90 days ago I didn't try to return them (at first).

I went through my stash of filters checking for any other signs of corrosion and I didn't find any but now I'm concerned I need to take steps. I guess I'll put a thin coating of oil over the bottom plate as soon as I get a new one just to make sure they don't corrode in my stash. Since these are the only synthetic media filters I have found that fit the 4.0L engine I'll continue to purchase them as long as they're available.

I contacted the royal purple people and they claim they stopped selling these filters a few years ago. I asked where they came from and the answer I got was that Champion makes them (& apparently distributes them under Royal Purple's name). The packaging shows "contact royalpurple.com" but royal purple said I'd have to contact Champion directly. I was less pleased about this.

So, I considered ordering 2 more filters from the parts store and after I picked them up I could return the 2 corroded filters as a new purchase in the 30 day window but I decided against it. I asked one of the counter guys that I see apparently too often what he suggested. He discussed it with a few of his colleagues and they reluctantly accepted them as a 'warranty' return. I was pleased that I was able to get them replaced without having to purchase a new pair but they shouldn't have been corroded in the first place. If you also purchase these filters check their condition when you buy them so you don't get a surprise later.

 

if the RP filters are the same size (length) as the MotorCraft FL-2021’s, then they are shorter than the Jaguar branded filter & have less filtering capacity. I have a MotorCraft stashed as a backup should I have a filter failure, but don’t think they are as effective as the Jaguar filter.

i do like the synthetic filter media, it’s a big step forward, IMO.

Mobil 1 used to have a great filter for our cars, but discontinued it some time ago. I think it was made by Champion to Mobil’s specifications (also synthetic media). Champion makes a lot of filters with different specs. There are some very interesting filter comparisons online.


Z

 

the jaguar/mann micro top filter media is trash

without exception they have wavy pleats

 

please don’t stop there, very curious to learn about the bad reputation.


Z

 

https://bobistheoilguy.com/forums/th...t-open.335154/

look exactly like the two i cut open. the aj16 filter is even worse.

the fiberglass media k&ns are out there but even with 15k changes a regular wix/microguard works good enough.

 

So far all I see is anecdotal information. My Cut open Jag filters look normal, but have only seen a maximum of 5,000 miles service. No head to head comparisons of the Jag filter vs ??? ?

my Blackstone lab reports of the past 50,000 miles are showing zero metal, iron, etc. and are showing more than 50% of additive package left in the oil @ the 5k mileage mark. Just lucky I guess.

Z

 

I use the Royal filters too. I read some test reviews and they got great reviews. I used to be a Sheep and always used Fram ( never again). Fram has great PR but their filters are crap. I haven't had any trouble getting the royal filters for my 2000 - XK8. But I will check out the corrosion issue. I use Mobil 1 filters on all my other cars if I can get them.

 

i use the Royal Purple Filter as Amsoil does not have one made and branded for them in this size. Have cut a few open. Not easy as they use a rather thick casing. Found it to be very well made and in the same manner as the filters that Champ makes for Amsoil.

My thoughts regarding the corrosion in the samples that you received is that they were in a damp environment for an extended period of time, perhaps a roof leak in a warehouse. This is unpainted metal relying upon oil to keep it coated in use. Many other filter brands such as Amsoil (Champ), Honda, etc. plastic wrap the filters before boxing. The Royal Purple is not which could be the cause.

It is a great filter. I just ordered ten, so they are available.

if it is no longer made, there is always Bosch or Purolator or perhaps Mobil 1 will make a synthetic version.

 

I just ordered a Bosch!

 

Do the Bosch filters have full synthetic media? The RP filters are the only pines I've found so far. Thx

 

No idea!

 

Bosch is full synthetic filtering media.

 

Is that a good thing????

 

yes, it is. For two reasons. The synthetic oils might cause deterioration in paper media and overall the filter material lasts much longer. There is actually a third which is that the fine filtering without excess flow restriction is not possible with conventional media.

Here is an interesting tidbit. For quite some time some the quality car manufacturers have specified smaller filters (reducing size even for existing part numbers for older models) and scheduling filter changes every other oil change. My 08 Honda manual is quite clear with this. Perhaps if one is using a good filter, there is a savings.

I have opened up filters being used for very long time periods and with multiple changes, even sent the interior media for testing. Unless the oil becomes burnt which ruins the filter, all of the samples were still useful for continued filtration at spec. Oil analysis also showed that particle contamination was not an issue.

Perhaps buying the best filter and using it double gives better wear protection and a built in savings making up for the extra cost.

It is kind of interesting when one thinks about it. No different than my use of synthetic oil extending my change requirements due to usage pattern. It pays for itself. The idea is not to get stupid about it and be aware that manufacturer recommendations in some cases are not in the users best interest. In other words, be reasonable and look at data. Sometimes the best product or usage profile is not at all the most expensive, however it takes time to learn the details outside of marketing hype.

 

So what's the part number for this bosch filter please? I haven't found it listed in my local auto parts stores when searching filters for my car. Only the RPs. Thx.

 

3978

 

The one I bought is for a 2002 XK8, no. 72209WS Bosch. According to partsgeek is a synthetic medium, and I believe the WS stands for Workshop which means ????????

 

If you compare the sizes of oil filters that are recommended for the 4.2, they are all over the place!
Some are taller. Some larger outside diameter. What's best?
WIX is 4.685" tall and 3.150" outer diameter.
Bosch is 4.15" tall and 3.031" outer.
Mann is 4.68" tall and 2.79" outer.
Pretty big difference.
I wonder what the Jaguar branded filter size is?

 

my Jaguar EAZ1354 measures
4.675 x 3.0485 with a basic Chinese steel caliper. About the same as the WIC.

I'm going to try a Mann filter next.

Mann-Filter W 719/7 Spin-on Oil Filter

Mann-Filter W 719/7 Spin-on Oil Filterhttps://www.amazon.com/dp/B000CB94Z4/ref=cm_sw_r_cp_api_glt_fabc_81MSGXRYYTKBN6HED311

 

I looked up filters on Rock-place and here's what I find. The Bosch filters both have cellulose paper media including the ones mentioned here. Fram has 2 also, FP5618 is paper, PH is a blend, as is Motorcraft. The most expensive ACdelco makes no mention of media, same for several others. I have use Wix and Motorcraft with no issues. TM