Recommended spark plug

[sbobev (Steve)]

@Ptipon

What is the latest recommended spark plug for the 5.3L HE?

From the manual:

We discussed spark plugs last week on the XJS side:

Chasing Down Mild Idle Stumble

BR7EF is the specified plug for the 6.0L, just confined with my manual that this is the same plug for the 5.3L V12 as well (at least those with the Marelli ignition as mine) [24%20PM] Aside for the heat index, the TR5 plug is “projected” (BP5EF) while the other one is “non-projected”. I have no idea what that means in practice and will be the first to admit that in almost 10 years of ownership, I haven’t gotten my engine to the point where a coin can be balanced on top of it…