Absolute best spark plugs?

Well its about that time I'm almost at 60K, so I'm gonna go ahead and do this before I go on vacation in April. I recently purchased a camper so I want to squeeze every little bit of power and efficiency out of my beast. I've heard positive things about Bosch Platinum +4s' - like they put out the best "bang" - to negative like they're junk and the tips break off into the cylinder. I've heard of Iridiums, but don't know much about them.


So I'll ask all you car peeps, what would be your choice for spark plugs? Cost isn't an issue since its only done once every great while. As far as the other stuff I use, I use Mobil 1 full synthetic oil and K&N air and oil filters.

Also do changing to high end spark-plug wires make any difference? Thanks for any help you can give me...

Re: Absolute spark plugs?

Platinum and iridium plugs last longer with less wear to the electrode. That's about it, I'm afraid. As long as you get plugs with the right dimensions and heat rating, that's really the best you're going to be able to do. I mean, you could index your plugs, but I haven't seen any tests showing that indexing is actually effective.

Plugs and the rest of the ignition system just serve to ignite the air/fuel mixture. You can't really change how "well" the mixture is ignited; it either ignites and the flame front propagates or it doesn't. If it doesn't ignite, then your ecu is going to throw codes and you'll know all about it. Same for plug wires as long as the insulation is intact. They either carry the energy to cause a spark and ignition or they don't, and your ECU will tell you you're getting misfires. If the insulation is breaking down, it can cause a short to the valve cover, and you can often see this by running the engine in total darkness and watching under the hood for blue flashes from the plug wires. If your plug wires are shot, just replace them with OEM wires.

This vehicle does have an electronic ignition, right? Oh, when you replace the plugs, definitely check the old ones for discoloration, signs of overheating, blackening, etc (useful diagnostic info), and do make sure you check the gap on the replacement plugs even if they're pre-gapped from the factory.

Re: Absolute spark plugs?

Are you going to replace the plugs yourself, or pay someone to do it? How often are you willing to replace the plugs? Sure, there are plugs that will run for 60-100k miles, but it's kind of like an unregulated incan flashlight burning alkaline batteries. Sure it operates, but with a weak yellow beam that is far from optimum for most of it's life cycle. Until someone invents a spark plug that includes a miniature file or sandblaster that operates every so often, spark plugs will continue to get dirty despite any whiz-bang marketing, and you will suffer from lacking throttle response, gas mileage, and possibly poor starts through most of the "useful" life of a 100k mile spark plug. I prefer to buy cheap spark plugs and replace them every 12-15k miles.

Click here for an interesting comparison of automotive air filters(including the K&N).

:buddies:

Re: Absolute spark plugs?

Diesel_Bomber said:

[...] and you will suffer from lacking throttle response, gas mileage, and possibly poor starts through most of the "useful" life of a 100k mile spark plug. [...]

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Oh, BS. Plugs and wires don't affect performance in any but the most contrived of situations.

Many of the top manufacturers including Mercedes-Benz are using platinum with excellent results. While working with them for many years is was very odd to ever diagnose a problem as the result of a bad plug. They'll go 75,000 plus miles easily in most higher performance engines and really do seem to suffer fewer deposits than standard plugs. Obviously some engines just burn cleaner than others but anything made within the last 5 years isn't likely to quickly foul up plugs.

Re: Absolute spark plugs?

likeguymontag said:

Platinum and iridium plugs last longer with less wear to the electrode. That's about it, I'm afraid. As long as you get plugs with the right dimensions and heat rating, that's really the best you're going to be able to do. I mean, you could index your plugs, but I haven't seen any tests showing that indexing is actually effective.

Plugs and the rest of the ignition system just serve to ignite the air/fuel mixture. You can't really change how "well" the mixture is ignited; it either ignites and the flame front propagates or it doesn't. If it doesn't ignite, then your ecu is going to throw codes and you'll know all about it. Same for plug wires as long as the insulation is intact. They either carry the energy to cause a spark and ignition or they don't, and your ECU will tell you you're getting misfires. If the insulation is breaking down, it can cause a short to the valve cover, and you can often see this by running the engine in total darkness and watching under the hood for blue flashes from the plug wires. If your plug wires are shot, just replace them with OEM wires.

This vehicle does have an electronic ignition, right? Oh, when you replace the plugs, definitely check the old ones for discoloration, signs of overheating, blackening, etc (useful diagnostic info), and do make sure you check the gap on the replacement plugs even if they're pre-gapped from the factory.

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Exactly what he said. To put it simply, either the fuel/air mixture ignites or it doesn't ignite. None of these hyped up spark plugs can really change that to make it ignite "better". It's kinda like lighting your stove with a blowtorch or a match. No matter what you use the stove gets lit, it doesn't change the performance or efficiency of the stove.

About the only advantage of some of the exotic platinum/iridium spark plugs is longer interval between changes. Some manufacturers might recommend them on some engines where the spark plugs are hard to access they want to extend the maintenance interval. Even then I've taken out regular $1 copper spark plugs after 80k-90k, which is probably 3x the recommended lifespan, the gap was almost double the factory spec, but there was no noticable effect on performance. Unless you have money to burn, I wouldn't waste the money on fancy plugs. There are much better things to waste money on.

... what ever happened to taking out the sparkplugs every once in while,
cleaning if necessary (and adjusting the carb mixture so they burn a nice dry dark brown, instead of black and oily) and gapping with a feeler gauge?

...same thing that happened to my '69rs bmw I guess..

Re: Absolute spark plugs?

likeguymontag said:

Oh, BS. Plugs and wires don't affect performance in any but the most contrived of situations.

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I respectfully disagree. You have your experience and I have mine, and we are both entitled to our own opinions. My experience has shown a universal increase in mileage and performance with clean vs. dirty spark plugs. I'll continue to keep my spark plugs clean and reap the benefits of doing so.

If you do the work yourself it takes half an hour and costs $12 to replace the plugs on your average V8. You don't have to save much gas to break even on $12. If you have to pay someone then that moves out the break-even point, which is why I asked the OP if they would be doing the work themselves or hiring someone. These points will get even more important when gas prices go back up.

:buddies:

Re: Absolute spark plugs?

InTheDark said:

[...] It's kinda like lighting your stove with a blowtorch or a match. No matter what you use the stove gets lit, [...]

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Brilliant analogy. You make it so simple.

TedTheLed said:

... what ever happened to taking out the sparkplugs every once in while,
cleaning if necessary (and adjusting the carb mixture so they burn a nice dry dark brown, instead of black and oily) and gapping with a feeler gauge?

...same thing that happened to my '69rs bmw I guess..

Click to expand...

Hey, I compare the plugs on my fuel-injected, electronic ignition honda. It helps me know if my injectors and EGR ports are clean and flowing equally. Care to tell us more about the bimmer?

well since I replaced my plug wires with MosterCables (TM) my car's bass and high frequencies are definitely much punchier more transparent, respectively..

..oh, it was a factory red 1969 bmw motorcycle..touring tank, earls forks..
..it was sold, cheaply, in my absence.. :shrug:
45 mpg..drove it from NY to Vermont and college, summer, winter, brrrr -- those valve covers made good hand warmers..

anything else ?

TedTheLed said:

..oh, it was a factory red 1969 bmw motorcycle..touring tank, earls forks..
..it was sold, cheaply, in my absence.. :shrug:
45 mpg..drove it from NY to Vermont and college, summer, winter, brrrr -- those valve covers made good hand warmers..

anything else ?

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Nah, the bikes are truly beautiful, but my real lust is for the 2002 and 3.0 CS.

The absolute best spark plugs, are the most Expensive plugs you can stomach can take before the gag reflex kicks in.

I would definitely go with platinum, have heard much naysaying regarding iridiums and the multi-pronged plugs. Had nothing but reliable performance with AC Delco Rapidfires in my GM vehicle. I have tried bosch platinums and the electrode was so narrow that they eroded much too soon.(under 12k). Generally speaking the manufacturer recommended ones should perform well enough and the gimmick/high performance ones will have longevity issues. Have fun with the camper:twothumbs

Re: Absolute spark plugs?

Diesel_Bomber said:

I respectfully disagree. You have your experience and I have mine, and we are both entitled to our own opinions. My experience has shown a universal increase in mileage and performance with clean vs. dirty spark plugs. I'll continue to keep my spark plugs clean and reap the benefits of doing so.

If you do the work yourself it takes half an hour and costs $12 to replace the plugs on your average V8. You don't have to save much gas to break even on $12. If you have to pay someone then that moves out the break-even point, which is why I asked the OP if they would be doing the work themselves or hiring someone. These points will get even more important when gas prices go back up.

:buddies:

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It's not a question of clean vs. dirty spark plugs. The original question was whether the fancy high end spark plugs were worth it over standard. If the spark plugs are old, corroded, and just not working properly, then a new clean set will give you a performance increase. But if you compare a new, working $0.99 copper plugs to the fancy $20+ platinum/iridium multi spark plugs, you will not see a difference. The plugs either work or they don't. Same thing goes for the fancy spark plug wires.

Now if you have to change the spark plugs every 12k to 15k to keep the performance optimal, then I would start looking for the reason why the spark plugs are degrading so fast. Most manufacturers recommend 30k between changes, and thats usually a bare minimum, I wouldn't be surprised to get at least double that amount out of a regular set.

ITD, KDOG asked.........

KDOG3 said:

....what would be your choice for spark plugs?

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And I replied................

Diesel_Bomber said:

I prefer to buy cheap spark plugs and replace them every 12-15k miles.

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Burning fuel is dirty. 12-15k miles is before I notice any performance drop; which is the whole point. I'm not understanding the issue here.

:buddies:

Diesel_Bomber said:

Burning fuel is dirty. 12-15k miles is before I notice any performance drop; which is the whole point. I'm not understanding the issue here.

Click to expand...

You're right, I can't discount your experience, but this doesn't sound like a healthy vehicle. Have you thought about checking the response time of your oxygen sensor? Flow-matching your injectors? Or is it carbureted? In that case I'd definitely have to defer to your experience.

From what I've read the platinums do last longer, however the rub was getting them out without damaging the threads after 100k especially if the head is aluminum. Simple maintenance as Diesel Bomber is suggesting will negate this risk. I remember a cleaning device we used to have. A bag with some fine abrasive in it, you hooked shop air to it and the plug fit in the side. After 20 seconds or so the plug was nice and clean. File the center electrode flat, regap and wala like new. Hardly ever had to buy plugs really. Ahhh, the GOOD ole days. For me I just use the regular Motorcraft or AC plugs and check em once a year. My 83 Delta 88 hasn't failed to start in -15f weather yet.

I might try platinums on my chrysler minivan, it's gettin close to 60K, and I have a question for you experts.

How do you guys change the inner spark plugs on minivans? between the engine and firewall?(Plugs 5 and 6) I have tried Yoga, Vudu, rabbits foot, etc and they are always a pain in the *** to change, do dealers hire Hobbits to get in there and change them?

Any tips?

Thanks!
AlexGT

likeguymontag said:

You're right, I can't discount your experience, but this doesn't sound like a healthy vehicle. Have you thought about checking the response time of your oxygen sensor? Flow-matching your injectors? Or is it carbureted? In that case I'd definitely have to defer to your experience.

Click to expand...

My experience comes from working on engined equipment of all sorts(cars and trucks, log skidders, fork lifts, backhoes, water pumps, generators, etc.) in a professional capacity for most of my working life, not just my own personal vehicles. TBI/MPI, carb'd, propane, mechanical injection, etc. Carb'd is definitely nasty and you'll notice a performance decrease within 12k miles, no doubt. Provided the adjustments are right, propane is good for nearly forever.

Keep in mind I'm not saying that a spark plug that has more than 15k miles on it won't work, just that it won't work as well as a new one. Therefor my preference is to replace it sooner rather than later. Anyone reading is urged to do their own research and make their own choices.

:buddies: