Lude Generation

Does anyone have any tips on how to remove a spark plug that's so tight the ceramic (or worse) is at risk?
I've tried most things, including applying a bit more force than I'm happy with.

drop oil down, leave it overnight, then tighten it first and then attempt to remove - maybe run the engine for 5 mins as heat will apparently help as well

Id run it round the block to heat it up, remove the plug leads then dump some penetration spray down there whilst its hot/warm, and let it soak through as it cools down, then get my 3 foot breaker bar on it. Its not that you need 3 foot of leverage, but you will get better feel and control then trying to use an 8 inch ratchet...

If it wont budge after that - get an impact gun on it - if its rusted in the shock will help break off the rust without tearing the threads (or at least less likely to than removing with a ratchet or bar).

This happened on my Lexus. As Scott mentioned my mechanic got a breaker bar on it but it was seriously tough! God knows why some people put them in so tight.