Hi all, look I'm not sure if this has been covered before. I did a search and nothing came up.

I'm located in Australia, and have just bought my first Trans Am.

what you might find hard to believe is that tow of your big brand plugs such as AC Delco and Autolite are not off the shelf items here. There are a select few that are importing them, other wise our market is flooded with NGK, Bosch and Denzo plugs.

I recently have used Autolites (I sota do work more on Fords then GM stuff, so that's why I chased them down in the first place) and I so far have found them to be good.

But I was wondering what have most of you guy's found works best or worst?

Directly what are your thoughts on Ac Delco and Autolite. I know this can bring out a lot of brand bias comments, but lets get down to what has a good reputation and what people have found does not. I'm really interested in finding out how these two plugs are viewed in the USA. Like I said over here they aren't much heard off so I'm really keen to here form all of you.

Francis.

 

Personally, I think you'd be fine with any of those brands.

The one's I've been least impressed by are Bosch Platinum. But, I haven't used them in years, and not in my 3rd gen, so I can't say you shouldn't use them.

The multiple electrode plugs don't seem to hold much favor around here. I've never tried them.

10 years ago, Jacobs Electronics told me to stick with copper plugs when using an upgraded ignition. Their point was the fancy plugs compensate for weak ignitions, and actually detract from performance when the ignition is up to snuff. Don't have any data to contradict what they said, but that's what I've been doing since.

I've been using NGK u-groove plugs in the 396. Probably contradicts the Jacobs recommendation, but I haven't had any problems with them. In the Camaro, I use Accel shorty plugs for header clearance. Also no problems with them.

 

haven't really tried much with AC delco plugs myself but on my mazda rx7 which by the nature of the beast isn't the greatest as far as combustion properties use NGK plugs. my honda I also tend to use NGK plugs.

most plugs you should be fine with. multiple electrode plugs generally aren't performance based but more for longevity. though the bosch +4 tend to foul out easy so guess so much for longevity there. platinum plugs are kinda for longevity also. copper should work fine they generally just wear a little quicker but that shouldn't be that big of a problem.

but as stated above my personal PREFERENCE is NGK. it isn't backed up by anything or extensive trial and error. just what I heard works well and it seems they have a good history. at least they seem to in the import playground

 

Cant say anything proven for one rand over another. In teh past when I used to drive chevy's it seemed I was replacing the AC's on a consistant bases to keep them from fouling, but the work trucks were never tuned to perfection either so that is my fault they kept fouling.

Since growing older/wiser I hae switched over to all Ford trucks and instlled new Motorcraft's right away and the first truck has put on over 120,000miles on same glow sticks with no hiccup, I finally changed them out of guilt and they looked fine.

The race car I've tried AC's, Champions, and have been using Autolites, no real way to say if any are better than the other since they get changed every 2 months for my own piece of mind striving for consistancy.

The race truck has had the original NGK's in there for 3 seasons and look beautiful so we just leave'em in there. Seems at our track Autolite AR plugs or NGK seem to be the choice of most to light off these big dollar engines and in relity in N/A engines have never heard anything bad about either.

So long as everything is working properly tune wise it would take a loong test period to try and decide if one is really better than the other and most of us change plugs too frequently out of guilt to fully realize any true results.

 

I put the NGK's in the 396 in the middle of the '03 season. Before going to Pomona in Nov '04, I picked up a new set, "just in case".

I still haven't put them in. When I pulled the plugs while installing the new cam last weekend, they still looked good to go.