I know this has been asked before, and I've read all I could find, but they are all older and I can't find any plugs locally now that will work. On Amazon they have Autolite 23 but that's about all I've been able to find. I want one colder range and some advice on gap. There are no markings I could find on the plugs in there now, and my gauge was too small to read the gap, but it looked like about .055 or .060 so I reset them to .040. Looking for exact model numbers, thanks.

bump up. Has anyone replaced their plugs lately for a 2.8 turbo?

How much boost are you running? The widest gap up to OE spec and the hottest plug up to OE spec is what you should run unless you're having a knock problem. On an engine built for 87 octane, if you're running premium fuel which you should be on an engine that does not have a knock sensor, I doubt you'll need to bother the plugs with anything other than stock. I've gone 1 and 2 heat ranges lower but eventually went back to stock. I checked into it with NGK some time back and the rep reluctantly advised going one heat range lower in a conservative setup.

I always recommend NGKs for the 2.8. They are the best value for the money for the stock engine.

Here's some good info I wrote up about it a while ago: https://www.fiero.nl/forum/Forum2/HTML/126432.html

I don't know how much boost it is making, my buddy said it is a large turbo and it is about as fast as his Solstice. I am running premium. I could try stock and see if I get any ping.

quote Originally posted by countach711: I don't know how much boost it is making, my buddy said it is a large turbo and it is about as fast as his Solstice. I am running premium. I could try stock and see if I get any ping.

I doubt you'll have a problem at all with the stock plugs. Going with premium fuel should have afforded you all the protection against spark knock from plugs that you will need unless you're running high boost (in excess of 10 psi on the 2.8) which in this case I doubt because I suspect you do not have a boost gauge which you need to get right away. If there is any intercooling or alcohol injection, that will also work in your favor. Stock 2.8L compression is relatively low compared to what factory turbo cars are running now although with aluminum heads.