Plug choice

[burt ragio]

I am trying to choose spark plugs for my car. All stock for now. I have done some reading and now more confused than before. Copper, platinum, Double platinum or iridium. Just want a plug that will not give me any problems for 50,000 miles.
Also read in a post by a member Quote: I had Autolite Irdiums in my engine, XP103 to be exact. When I took it in to my dyno tuner to be tweeked I was down 30 HP. He did compression tests thinking I'd lost a cylinder. Nope. Stated the ignition was erratic. So he replaced the plugs with Autolite 103s, plain copper plugs, one heat range colder than OEM. My HP went back to where it was 2 years ago."

[RubberCtyRauder]

NGK 4177 TR6 are one range colder

[martyo]

NGK 4177 (TR6) gapped at .045

[RF Overlord]

What Marty said^^^

That makes at least 2 known cases of Autolite plugs causing ignition problems.

[ctrlraven]

Three sets of NGK TR6IX gapped at .035, zero problems and that's with the GMS coil connectors also. I've used the NGK TR6 in a few other vehicles, no problems with them either.

[fastblackmerc]

What Marty said^^^

That makes at least 2 known cases of Autolite plugs causing ignition problems.

I prefer to run the NGK's but I got a set of the Autolite XP103's for free. Have about 30K on them with no problems.

[burt ragio]

Just ordered the NGK 4177 tr6 plugs along with oil gas & air filter. All from rock auto. Thanks for all the helpful advice on plugs.

[RF Overlord]

Have about 30K on them with no problems.Mary's car ran fine for 27,000 miles before the issue started. I'm just sayin', if you do start to notice an issue, don't discount the plugs as being the cause.