Over the many years I have owned Jaguars from the XJ6 Ser.1 through to the XJ8 I know own, I have never experienced leaking sump plugs....whether they have alloy sumps as in the earlier models or metal pans as in the later cars.
It is usually down to ham fisted methods or shear laziness that causes leaks.
As for this BS about Jaguars leaking every where before the Ford ownership....frankly I consider this one of those long held bar room myths that have become self ebergising over the years to cover all sorts of excuses for sloppy workmanship usually displayed by service centres and back yarders.
All for the simple expeiancy of replacing a damn washer!!!!
Whether it be a Thackery washer.....know what they are???
Or an 'O' ring....never use a crushable or flat copper washer....and lightly torqued, the sump plug will last for years.
The same applies to the installation of an oil filter....screw it hand tight plus 1/4 turn.
I have seen twerps in service centres apply the filter wrench and tighten the bejesus out of it to the point it distorts the rubber seal!!!
Morons??.....that would be too kind!!

 

I'm not sure why this is so hard to understand. The point of the new design was to eliminate the problems associated with all the old designs. It is that simple - you guys can have all kinds of reasons why not to use it .. but that does not change the fact of why the design is the way it is.

I have been buying new Jaguars since the early eighties and my father's first new one was in the early fifties -- I wish my memories of the old ones were of dry garage floors.

If you don't want to use a new one and are happy with reuse or a work around .... then do what you want. Same goes for the filter. For my $30 bucks every two years --- it's an easy decision.

 

I see that you feel quite passionately about the filter and plugs that you use, and for that I'm sure you get some peace of mind. I, on the other hand, see no reason to throw even small amounts of time and money down the drain for no reason. I have not replaced the plug in mine since I got it and not a drop of oil on the garage floor. Now, if I do get even one drop, I'll be at the dealership in a moment getting a new one. My garage floor is 40 years old, has plenty of drips on it, a few more won't hurt it. I check my oil regularly, so if there is a leak, I'd notice it (but the amount of leak for a small drip normally isn't enough to cause a problem by lowering the oil level enough to notice it on the dipstick).

As for oil filters, I am a bit more passionate, or maybe cautious. I'm a firm believer in using a good filter, and that's why I've been trying to find someone here who can tell us what the OEM specs are so we can compare them to the ones at the parts stores. Ok, I know I could go to the dealership and get the filter, but as more of an academic exercise, I'd like to know what alternatives there are and why. All of this "XXX is a good filter, but I wouldn't touch the YYY filter with a ten foot pole" adds nothing to our knowledge base, but is great for eliminating certain low-quality filters from the fray.

With all that said, I'll continue to have my mechanic change my oil every three thousand miles and will keep an eye on the garage floor.

 

I'm really not very passionate about the oil plug or the filter -- I own fifteen cars -- and I don't have the the time or desire to worry about either. I am a car nut and over the past 30 + years of driving I have made my share of mistakes in my attempt to save a few bucks .... you learn a few things that stick with you and say ..........never again.

On some cars I use nothing but the OE maintenance items. I purchase them in advance to obtain favorable prices -- so no worries.

With low production vehicles the aftermarket is normally a compromise.