Originally Posted by Dancianne
There are no "special" spark plugs which would improve performance or gas mileage over the OEM's. For sure if there were such a thing, all automotive makers would already be using them in order to remain competitive. So, point is, the OEM's are the special ones and best you can buy. Factory engineers have already figured out which plugs are the optimum choice for every vehicle, and they are not going to shave performance to save a dollar or two because that would hurt vehicle sales. On a related subject, I do not advocate do-it-yourself plug changes unless you are both experienced and have the proper torque wrench. Given today's engine metals, tolerances, and do so at cold settings, I believe that it is imperative to be right on with factory specifications. Yes, dealer service charges are outrageous and over priced, but taking into account the life of modern plug technology, the cost is virtually nothing on a per mile basis. Gone are the days of yore when cylinder heads were made of iron and all one needed were a wrench and a 'feel' for what was about right.
Heh, to a point, you are correct. I still do most of my own basic repairs/maintenance on my own vehicles without a TQ wrench. Is it required? not really...not for spark plugs. Your dealer tech doesn't use one either. trust me, I know.
I use TQ Wrenches for lugnuts, head bolts, rod and main bearing caps, transmission and oil pain bolts, and anything to do with internals like gears, clutches or tranny work. Other than that, its just German Spec. That would be "Gudentight". I have yet to use a TQ wrench on my ford escort. Even the crankshaft pulley from when I did the timing belt just got cranked till it was tight.