lourias

I changed my spark plugs to the autolites equivalent to the motorcraft. Gapped then to .053 and my mileage has dropped by about 3mpg. Are the autolite plugs just garage or is the gapping way off or any ideas? If I remember correctly the gapping is suppose to be between .052 and .056. Any help would be greatful.

4x4dave

I can't speak for the autolites, i always used OEM (motorcraft) when my truck was stock. I think .054 is the stock gap. It should be listed on an emissions sticker on the hood somewhere if i remember correctly.

Your autolites could be a different heat range, maybe that's why your not getting as much MPG.

Tackle

Your gap is fine.

Autolites are fine.

Sorry I can't be of much help. Has to be a factor we aren't aware of.

lourias

Ok. You think not having a muffler would make that much of a difference? Right now I don't have anything past the cat.

Carcrazygts2

Autolites are garbage. They are not made to the same specs the OE Motorcraft plugs are. I suspect they are the wrong heat range for the engine.

lourias

Ok. Do you know what the heat range of motorcraft plugs are or the autolite?

Fordfan2006

Just get motorcrafts and be done with it.

lourias

I planning to. Just got to wait for a buddy to get them from work. $2 a piece is a lot better than 4 or 5