i just changed my plugs. i gapped them at .032 but the ones i took out where all different. they ranged from .040 to .045 not sure why.

As your plugs wear the center electrode will wear down and to a lesser extent the ground electrode. This is why your gap is opening up.
This picture is what you're plugs will look like if you keep them in till they start to misfire. It's a lot more exaggerated from what you have I'm sure but you get point.



This is from NGK's website:

This post was last modified: 09-21-2008 09:07 AM by Peej.

that makes sense. thanks

I'm still not 100% sure on what causes uneven spark plug wear. I mean. If you take them out and a gap difference of .08 can be measured between cylinders 1 and 3 I'm assuming the cause could be from more internal wear in the #3 cylinder from valve leaks of some sort.

.08 is such a small difference that I wouldn't even think about it...and what the heck are you using to measure your gap that close!?!?!?!

You're assuming that the metal in all of the spark plugs is identical. From a manufacturing process, there will be built in variables for the alloys the electrodes are made from which would mean it won't neccessarily be the same from batch to batch. For instance, one batch could be at the high end of acceptable where the next could be at the low end.
Another thing you would need look at would be the voltage differences between the coils on all the cylinders. You might have one coil putting out more voltage than another which would account for increased electrode wear.
If you had a valve leaking enough to effect spark plug wear you should also have idle and drivability issues. You can definitely hear leaking exhaust valves through the tailpipe. About the only time you'd ever have a burnt intake valve is if the thing was stuck open.

^ I was speaking theoretically, but I see what your saying. There are many different things that can affect the spark plug wear, but what I was talking about is a difference in wear between 2 cylinders. One would assume the plug with the least amount of wear is producing the least amount of energy. The plug with the most wear is producing the most energy. A plug with extreme wear is in a cylinder that may have issues that are minor now, but could develop into something severe later.

Has anyone with .044 gap achieve better gas mileage?

Can anyone validate this? I need to change plugs soon...