for normal mods this is way overkill, but for FI this is usefull.

 

Why? At what compression pressure would the stock system give up the ghost? There are 4 coils, so coil saturation at high RPMs would never be a factor, and the voltage is high enough to light at way crazy pressures, so where would the benifits be? Sometimes a little knowledge, misapplied can be costly to the pocketbook and performance. Stylis always has to toss in the irridium plug "solution" and this is also silly but it won't hurt anything and they should be good for 100k miles. Just don't get your hopes up for any power increases unless you have a vivid imagination. Why do they sell this junk? Because SOMEBODY will surely buy it! And yeah that fuel rail and gas line magnets surely take the cake! Extremely ingenious solutions to non-existant problems.

 

Yes sir!! everyone that has installed them over here in the norcal has had nothing but good things to say about them. :D

Nothing wrong with using the premium gas once in a while, now is it. I never push anything unless I have it on my car or have tried it out for myself.

 

Just changes the plugs every 30k and making sure they are gapped properly is just as good.

 

Iriduims rule! :D A little more expensive, but worth it. I drive my box pretty hard so I would have to change mine a little before every 30,000 miles.

 

Why?

 

Why not?

 

i like my engine bay to be clean looking with out all the extra spark plug wires imo

 

Because.

 

Its a 1.5 liter w/ high compression that is meant to be used for gas economy and commuting. Are some of these mods necessary for performance? Plus, the ECU has yet to be cracked. For those who want to runthis, props to you, but my 41k miles xB has been doing just fine w/o it.

 

Well, that answers everything!

 

Just doing a simple spark plug change restored the responsiveness I felt I was losing. Not gonna claim hp gains or anything but I can feel a difference when pushing the gas and it's idling smoother again. The gap on some of the plugs was up to .36 or so.

Another question maybe someone can answer without having to start a new thread.

I noticed the Denso and NGK plugs run a .032 gap while the Champions and Autolites for the same application run a .044 gap. Why the difference?

 

This is exactly the problem with many aftermarket parts! The Densos and NGKs are the only plugs recommended by Toyota and this is precisely why. Other plugs fit many other applications and if the thread size, reach, and heat range are the same (or close), they will list that plug for that application weather it is correct or not. That's why I only recommend the stock plug nowadays for ANY car! (Along with wires, oil filters,.....)

 

What other factors are involved besides these? thread size, reach, and heat range

 

Style, gap, and quality.

 

gap is changeable , style as in what how many prongs? quality is for ya know the consumer to decide if they want crap quality they get crap quality.

 

Well the beauty of this is that Toyota got some pretty smart fellers together when they were designing this engine and hammered out all these factors and options and picked the best plug for this engine and then installed them in your new car for no extra charge!SWEET!

 

And then you have the so called "experts" who will say differently.

 

just a lil fact stock obviously isn't always the best. . all i'm saying is that if the spark plug has the same reach , the correct gap , and the correct heat range it will work.

 

But will it work better? Cheaper?