340 Gets Terrible Gas Mileage

The "Champion plugs suck" thing is just total bullshit and wrong information. The only other thing I'll address regarding that is there are only a small number of plug manufacturers in the world and chances are pretty high Champion plugs are made by the same plug manufacturer that also makes the plug you run, instead of Champions.

That said, I'll add this as well. Not everyone "knows" how to calculate mileage correctly. More often than not, I see people making huge mistakes trying to figure mileage. Remember it takes multiple times calculating and then you have to average those calculations together over time, mileage and gallons burned. A lot and I mean a LOT of people just slap get it wrong wrong WRONG. Most of the time those mistakes work out to give incorrect results going the "WRONG" way.

So, before I touched a wrench on anything, I'd double and triple check MYSELF to make DAMN SURE I was doin it right.

Cause you may not be.