Do they help with anything? If so what? What kind of performance increases? Thanks

 

Nothing real special bout them. I used the NGK Iridium plugs in my 5.3 and a big difference in throttle response. They run bout 6 bucks a plug. They are a colder plug which is good if a tuning has been done and advanced the timing. Plus being Iridium plugs, they have a life span of bout 100k miles.

 

I Agree 100%...I have always had great luck with NGK's!

 

Having worked in an auto parts store I can tell you from what EVERYONE has ever told me, E3 plugs suck. I have talked to probably a dozen guys that ran those in chevy's and they did nothing back reduce power, reduce gas mileage, cause missfires, backfiring, etc. The only plug you should run in these is an iridium plug.

 

My older 5.7 runs fine on them, I wouldn't say they are the new hotness, but they work fine. I just did a tune up on my truck (Plugs wires cap and rotor. Plus seafoamed it) and I gained a lot of power back. I would venture to say that just changing the plugs helps, you would have to put two different types of plugs (new ones!) side by side to have a good idea of what the two plugs do for performance. I have seen many compairisons on the E3's versus other conventional plugs (Not the iridium types or newest versions like the Bosch Platinum +4) and they beat the competition. Obviously because they are a better engeneered plug. But it is still an improvement over the regulare plugs that are half the price.
So if you want to get the most out of your vehicle then obviously you need to upgrade your plugs with everything else that you change. But which one to go with is up to you. Unless you are engineering how your engine performs before it is even built and you are changing how your motor fires and when, (Multiple sparks per fire or not) that type of thing then that is the only way you will be able to tell exactly what plug to use and what heat that it needs to be.
That means that one plug will work better in a stock truck than in the same type of truck that has a different tune programmed in. Different conditions.

Sorry it is so long!