What is the correct plug gap? I put Denso platinums in. Manual says .06 and I've read .04, and .045. The Denso's came gapped at .04 and I opened them up to .06 which is a lot to open. The ground is not parallel to the electrode because I had to stretch them so far. It seems my fuel mileage went down after doing this. Should I have left them at .04? Is .06 only for a Delco plug? I'm confused!

 

Recommend sticking with AC/Delco plugs. Ethanol-free gas helps also.

 

And what would you recommend gapping them at?

 

if you do the iridium plugs like gm recommends its .040 and they come gapped if you do platinum its .060


and ALWAYS use oem spark plugs