How likely is plug removal going to be really difficult due to leaving them in for
218,000 miles or more ?

My 2001 MS XLS 3.0 4x4 has had the original plugs and wires in it since i bought it new in June of 2000. It now has 218,000 miles. i still get the same MPG in it. On Hwy and fwys,hills and mtns here in the desert of SoCal i get 20 range at 55 to 65 mph and rarely exceed 2500 rpm. I get the 22 mpg if Im traveling distance on fwys like to vegas etc. It just passed california emissions yesterday and has never failed 'emissions " That does suprise me. Its just a matter of time though and probably sooner than later. I am pleased, as this is my first new vehicle since the 60s cars i used to drive and they in no way were as trouble free as this MS . Those older cars engines ,i remember ,were finished by 100k or less. They were,however much easier to work on.Sorry,Im rambling ...

Back to my question:
How likely is plug removal going to be really difficult with 218,000 miles or more ?

here are my readings for those of you that are interested in this stuff.

707 rpm >.. %C02=14.9 %02=.0 / HC= 13 / C0% = .02
2554 rpm > %C02= 14.8 %02 =0 / HC=9 / . CO% = 0

 

That is incredible. I have not heard of any spark plugs lasting for over 200k! My guess is, if you did not overheat the engine and thus did not bake the plugs into the head - they'll come out just as well as after 60k. Are your spark plug wires OK after all this time too? You definitely want to replace them when you get to do the plugs.
Now that I'm thinking back to doing my last set of plugs (at 165k or so), they were looking almost as good as the new ones from the box. I'm sure mine could have gone longer without any issues.
I'm going to send this post to my friend with a Jeep and laugh at him. He is already jealous of me having to replace plugs only every 60k. The 218k will blow his mind

 

gapped every 10k, replaced as needed, a daily hack might see 60-100k,
a tuned racer will have them binned before 5k.
200+ is thoroughly impressive.

 

yep,spark plug wires ok too. nope,never over heated . Never add coolant except at timing belt change intervals when hoses and thermostat are replaced.
[Your quote] definitely want to replace them when you get to do the plugs.)]
Yes,just like at timing belt change time. Once Im in there I might as well replace anything that is likely to fail before the next 100K such as waterpump thermostat,all belts,hoses etc. The alt may be next though.Its the original too and I cant imagine it can last much longer.

 

I have 137k on my motor now with no misses or fowls from the plugs so I am leaving them until I do a major tune up in the winter time. Wires are ok also but will be changing everything when I get to it.