About a month ago I changed my spark plugs on my 4.9 and I think i forgot to gap them. They were either autolites or motorcraft I really cant remember, but I think autolites. Do they come pre gapped for your vehicle? The truck runs smooth as ever, but was wondering if there would be any ill effects resulting from it? Thanks

 

Bumping around in the boxes during shipping always makes me have to tweak em. Might be losing some efficiency.

Adrianspeeder

 

Dude I woulden't really worry about it. I seriously doubt you would even be able to tell the difference. Plus the plugs usually have a good gap on them to begin with. I think if there was something to worry about you would have already noticed the difference.

 

Since most aftermarket spark plugs are made to fit more than one engine they usually are not pregapped but they are pretty close. If your looking for the most horsepower and gas mileage you can get than you may want to double check the gaps, otherwise if the truck is running good dont worry about it. If the gap was too big the truck would run like crap and misfire under heavy acceleration since the high cylinder pressures would make it harder for the spark to jump the gap. Too small of a gap would result in a loss of efficiency from an incomplete burn in the combustion chamber due to a much smaller spark being exposed to the air and fuel.

-Jon

 

when ever i get autolites the cheapos there gaped fine