Just an update, I switched to copper plugs, having done so, the gas mileage has been drastically improved. I haven't yet gone through a full tank of gas to figure an exact number, but according to my trip odometer, and the gas guage I am probably getting at least 20mpg now. WOW hard to believe that spending $6.00 on plugs can make this kind of difference. Many thanks to "yal" that suggested the change, I never would have thought to change back to copper from platinum. Once the tank of gas is gone, I will recheck the numbers, but so far this seems like the fix. THANKS!!