There are a lot of things that you tighten where you can tell it is tight but you could crank it a bit tighter but if you do it might break. I am fairly confident I can tell when enough is enough.
I also have the wheel lug nut torque wrench that I might be able to use, and the video said how much torque, so it could be all right.
I'll know if the one plug comes out ok whether to proceed. Sure enough the next plug won't come out at all, but that's when I head for the garage on however many cylinders are still working! (Or get a tow :( )
