Question : Spark plugs recommendation - 3100 V6

[waterlight]

My daily driver is a 2003 Chevy Malibu with the 3100 (3.1L) V6. Just over 100k miles. According to schedule, it's time for a spark plug change. I'm looking for spark plugs recommendation and had two related questions with it.

First, what spark plug is the best to run in these engines as to brand (AC Delco, Autolite, Champion, NGK...) and type (Platinum or Iridium.)? I've been looking at the Champion part number 7940's but no personal experience. I do plan to call the chevy dealer Monday to see what comes plugs are installed at the factory.

My other two questions would have to do with the stock wires. The one source said I have 6mm wires. He said that I would notice a difference by going to 8mm wires ? Given these wires would be connected to the stock DIS, I wondered how much I would gain in terms of HP or fuel efficiency?

Long time reader, first time poster.

[IsaacHayes]

http://60degreev6.com/forum/f86/spark-plug-info-for-pushrod-motors-t37003

[Azrael]

Since it's a daily driver, save yourself some money and stick with the part numbers your car comes with. You won't see any less performance as there's negligable power/efficiency to be made from the ignition system. Choosing between copper, platinum, and iridium plugs is a matter of cost vs length of maintenance intervals. Most plug brands are good except Bosch.

The only reasons to switch to aftermarket plug wires is if you're getting ignition noise in the electrical system that new wires doesn't cure or to colour co-ordinate your enginebay.

[waterlight]

Issac, I did a search for spark plugs and did not find that thread you posted. Could the admins make that a sitcky or something?

Azrael - I don't think I'm getting any ignition noise, but will pay more attention next time I'm driving it.

Thanks guys!

[3400-95-Modified]

Issac, I did a search for spark plugs and did not find that thread you posted. Could the admins make that a sitcky or something?

Azrael - I don't think I'm getting any ignition noise, but will pay more attention next time I'm driving it.

Thanks guys!

Thats because its located here.

60DegreeV6.com > Forums > Site Related > Site Articles > Miscellaneous > General Info/Tips > Spark Plug info for pushrod motors.

AKA Old Articles section on the sidebar.

People need to look there more often, there is a lot of info over there.

[bszopi]

Once we move over to vb4, everything will be jacked up, err, rearranged again. I will most likely have to have a an old site set up somewhere for the articles until everything gets transferred over to the new setup.

[carbon]

Most plug brands are good except Bosch.

That's a little harsh... just because some idiot thinks that just slapping in some Bosch +4s in their GM engine is going to somehow light up the world doesn't mean that Bosch is crap.

[mongo]

I dunno... When Bosch first came out with platinum plugs I bought a set with confidence based on my history with their other electrical products. The plugs cost a fortune and caused no end of misfires and misery. I ended up putting in some plain old Champions and the problems all disappeared. It's been more than a few years since I have tried their plugs and they may have corrected all of the problems long ago, but given how difficult plugs can be to get at and change, I still don't recommend them to ANYONE...

[payback]

i threw in some +2's when i first got my car, was @ 185k miles...cars@230k now with the same plugs. i did get a random misfire code a few times within the first few thousand miles then it went away.
i dont think its the plugs i really think its a combination between them being a colder plug and the SFI itself, which apparently is random misfire prone to begin with. car runs REALLY well with mid-grade gas too.
i will be using ac delco iridium in the 3400 though (if it ever gets done). ive heard some good things and no bad about them.

[pocket-rocket]

That's a little harsh... just because some idiot thinks that just slapping in some Bosch +4s in their GM engine is going to somehow light up the world doesn't mean that Bosch is crap.

But, if you go with Delco's, you know that's whats meant to be in your car.