spark plugs

[Guest]

Looking to upgrade my spark plugs. I know the saying "if it is not broken don't fix it" but I cannot help it. I just love tinkering with stuff.

Any ideas on which spark plugs to get? Bosch 4's, Denso, iridium plugs, two points, four points??? There are so many, but I would like to get good ones. Currently I am interested in getting good wires and plugs. Looking at the Bosch 4's but heard that the other metal, iridium, is stronger (maybe better)???

If someone could help me out, that would be great.

Thanks,

Ryan

[gomer]

What happens with the multi ground electrode plugs is that the spark jumps to the best ground each time , as one heats up the next one (colder) becomes better ... realistically I don't think it makes a measurable difference in power or economy.. I always use a platinum plug ,, whatevers on sale that week... with that said some manufacturers use 2 or 3 ground electrode plugs as original equipment ,, I believe for emissions ... my thinking is that it probably extends plug life for those 100,000 mile tuneup intervals but emissions and fuel economy are probably unaffected until you go beyond the normal service life of a normal plug.

I can tell you unequivocally that the original "split-fire" plugs were worthless...

I can also tell you that if you burn ANY oil you want a single ground electrode,, preferably platinum (usually a thinner center electrode for a more "concentrated" spark) and one range hot.

[Phatbowler]

Fuel Economy

Well that is the main reason of changing my spark plugs, I want an ease of mind that I am getting good fuel economy out of my spark plugs. My car is getting close to 100,000 miles and I do not know when the spark plugs were last changed. So I wanted to make sure that I get a good spark plug for my Festiva.

Thank you

[CryptokiD]

i grew up with gernam cars and consiquently, awalys used bosch for my sparkplug needs. i have carried that on even to modern times and modern engines. bosch awalys works great for me, and their line of plugs called "supers" are cheap and work great. i run supers in everything i own.

[darkdan]

Coppers.


They are the most cost efficient. Platinum has a higher resistance. Iridium does nice, but it's 7 to 12 times the cost of copper.

Sure you have to change copper plugs more often, but on our motors it takes 5 minutes.

Of course, on my other cars I run double plats because I don't want to have to deal with it.

So copper offers the performance of iridium at the cost of....copper.

I completely agree that all the gimmick plugs are just gimmicks.

[gdawgs]

I agree with darkdan. Just get some cheap coppers, they work well and it only takes a few minutes, so who cares if you don't get 100,000 out of them. In one of my engineering courses, one group did an experiment on spark plugs to see if certain brands or types affected output. They bought all kinds of different plugs installed them in their test cars(they used two different vehicles, a pickup with a V-8, and a small car with a 4 cylinder), then did several runs on the dyno. Results, the cheap Champion coppers actually produced the most power. However, if I remember correctly, there was no statistical significance between any of the test groups. Translation=it doesn't matter, just buy whatever is cheapest.

[fastivaca]

It might be interesting to redo the tests after all the plugs had been run for 10,000 miles or more.

Ian
92 GL Sport (running Bosch Platinums)
Calgary

[yvanlavoie20]

ngk

ngk on japan made car run great and low cost...avoid champion on FORD engines (not mazda). i have many bad experiences with them...

[Phatbowler]

Just tried to take my spark plugs off. Couldn't do it though, the plug socket with my tool set only had a 5/8" spark plug socket. I guess I need a different socket. I saw that there is a 9/16" plug socket out there, I will try that one.

Thanks

[gdawgs]

You need a 13/16ths.

[HappyMom]

Bummer, a 13/16 socket will probably cost me more than a set of plugs...

I was expecting that the standard 5/8" would work, or at least some of the other deep sockets I have: 3/14" 9/16" 1/2" & 7/16"

[Phatbowler]

Thank you for that information on 13/16" socket. I was bummed that I could not check my spark plugs, on the other hand, I should get back to my college work anyway.

Thanks

[Phatbowler]

Finally got my spark plugs changed. The center electrode was white and the center stump was sloping on one end of all of them. But I did replace them all with Bosch Platinum +4 and I could tell the difference right away. I had more horsepower, hopefully I will have even better gas mileage than I am already getting.

I was so stoked that just changing the spark plugs could make that much of a difference.

Thank you for all the replies and posts.

Ryan

[gdawgs]

Probably about 98% of spark plugs are going to be either 5/8 or 13/16. Every now and then you'll see a 3/4. Then there are a few oddballs. I have some really old snowmobiles that use NGK A-7 plugs and they are HUGE, over 1" can't remember exactly though.

[darkdan]

Another victim of clever marketing.....