For longevity? better performance?My Odessy has them and they are 25 dollars a piece. Would a copper do just as well but not have the longevity?
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
Why are manufacturers putting in iridium plugs?
- Thread starter Car Luver
- Start date
- Status
- Not open for further replies.
longevity, usually.
the cost to replace for most people isn't just the cost of the plug it's also the labor, which at $70-80/hr can make those $5 plugs cost a lot more over time.
The labor is the same regardless of the cost of the plug. But those $25 plugs only need to be replaced every 100k. If you get 33k from the copper jobs, you'll need to replace them 3 times to get the same 100k. (and 33k is optimistic but it makes the math easier...)
so $25x6=$150 +200 labor =$350 once in 100k
and $5x6=$30 +200 labor =$230 (33k) x 3 to get 100k)=$690
of course, take the labor out and do it yourself and the math swings to favor copper (if technically compatible).
the cost to replace for most people isn't just the cost of the plug it's also the labor, which at $70-80/hr can make those $5 plugs cost a lot more over time.
The labor is the same regardless of the cost of the plug. But those $25 plugs only need to be replaced every 100k. If you get 33k from the copper jobs, you'll need to replace them 3 times to get the same 100k. (and 33k is optimistic but it makes the math easier...)
so $25x6=$150 +200 labor =$350 once in 100k
and $5x6=$30 +200 labor =$230 (33k) x 3 to get 100k)=$690
of course, take the labor out and do it yourself and the math swings to favor copper (if technically compatible).
You're not shopping in the right place. For example rockauto.com's most expensive plug (for a 2003 Odyssey) is a $12.81 NGK, and there's also an iridium NGK for $6.22. The catch is they come in sets of four...
yep, labor is definitely an issue for plugs on a lot of new cars. One of the reasons I love the I6 in my BMWs. Plugs are an easy 15minute job. I can even see all of them .
Haven't really seen much discussion of it, but many of these choices by the automakers derive from the need to warrant emissions-related components for 100,000 or more miles. In other words, if the component potentially affects emissions, it must either last the 100K or the automaker must repair or replace it free during that period. This is the reason for such expensive standard goodies as stainless steel exhaust systems and, yes, iridium spark plugs. Conventional plugs don't last anywhere near 100K miles.
However, with many of these long-life components you get what you pay for. My Escort wagon still has its original exhaust system after 287,000 miles. Sure beats buying a new one every couple of years as I've had to do with older cars.
However, with many of these long-life components you get what you pay for. My Escort wagon still has its original exhaust system after 287,000 miles. Sure beats buying a new one every couple of years as I've had to do with older cars.
I don't have a problem with paying more for a plug or other component that will last over 100,000 miles. I just changed plugs in my girlfriends Jimmy that had over 159,000 miles and they still looked good. Just did it for maintenance reasons. My plugs have about 175,000 on them and the car still runs smoothly and gets 25 mpg. Since I usually change them myself, I prefer plugs that are more expensive but last much longer.
ekrampitzjr (gads that's hard to type...) makes an excellent point: warranty costs.
here's a consideration: if you have under 100k and have replaced the plugs with non-iridium plugs (gotta ask why, tho), what does this do to any warranty issue that may arise? Agreed, only related issues can be voided by use of non-approved parts, but an awful lot can be easily interpreted as plug related, and therefore give the dealer an out.
here's a consideration: if you have under 100k and have replaced the plugs with non-iridium plugs (gotta ask why, tho), what does this do to any warranty issue that may arise? Agreed, only related issues can be voided by use of non-approved parts, but an awful lot can be easily interpreted as plug related, and therefore give the dealer an out.
Car Luver
Thread starter
100k emmision warranty? are ya sure. I could swear its 50K.
Toyota specifies 120,000 mile intervals with iridiums in the 4.7 V-8. On that engine in a Tundra labor is not an issue, they are as easy to change as on a BMW. BMW uses a special $15 NGK platinum plug for 100,000 mile life, not just a regular Bosch platinum.
Platimum or iridium is used if the ignition is DIS/waste spark because there are twice as many firing events and the polarity isn't the same on all plugs. This causes rapid wear on normal plugs.
Automotive aside, an understanding of basic plasma physics goes a long way in revealing why spark gaps wear and what gains are to be gotten from the use of different electrode materials. It all comes down to positive ions and the AMU of the gas used to generate the plasma.
Automotive aside, an understanding of basic plasma physics goes a long way in revealing why spark gaps wear and what gains are to be gotten from the use of different electrode materials. It all comes down to positive ions and the AMU of the gas used to generate the plasma.
What advantages do iridium plugs offer over platinum plugs?
Platinum plugs were the original 100K mile sparkplug. Iridium seems to be something new.
Platinum plugs were the original 100K mile sparkplug. Iridium seems to be something new.
I do not think Platinums were ever rated at 100k miles. Plats were 60k and Iridiums were 100k.
I have an excellent paper that was published by the developers of the Iridium plug. With tons of measurements showing why the Iridium provide better fuel economy and longer life than Platinum. I just don't know where to post a pdf document. Any suggestions?
I have an excellent paper that was published by the developers of the Iridium plug. With tons of measurements showing why the Iridium provide better fuel economy and longer life than Platinum. I just don't know where to post a pdf document. Any suggestions?
Ford has been calling platinums 100k mile plugs for a decade (which, not coincidentally, is how long they've been using them).
I think GM is the same.
I think GM is the same.
Not necessarily..Ford was using DIS back in 1991 (if not earlier) and didn't start using platinum plugs until 1994 or 1995.
I have no idea what the service interval for non-platinum plugs on those DIS applications is, probably 30K.
I have no idea what the service interval for non-platinum plugs on those DIS applications is, probably 30K.
My point was that a DIS/waste spark system causes accelerated electrode wear and that platinum was introduced specifically to combat it. The longevity of platimum/iridium is not simply a selling point when waste spark DIS is involved, it's required engineering.
If Ford didn't use them they either screwed up or their system wasn't waste spark/dual polarity. Even Ford can't change the laws of physics. Toyota began using DIS in 1987 and platinum came stock on the cars involved for these very reasons. The service interval on those were 60K. 30K seems quite high for a non-precious metal electrode used on DIS but they may have been something more robust than copper but less than platinum. Or the interval may have been shorter than you recall.
I can't complain about the cost of car plugs though. Try buying Champion fine wire iridiums for an aircraft engine. They're $55 apiece and come two per cylinder. $300 for a plug change hurts no matter how you cut it.
If Ford didn't use them they either screwed up or their system wasn't waste spark/dual polarity. Even Ford can't change the laws of physics. Toyota began using DIS in 1987 and platinum came stock on the cars involved for these very reasons. The service interval on those were 60K. 30K seems quite high for a non-precious metal electrode used on DIS but they may have been something more robust than copper but less than platinum. Or the interval may have been shorter than you recall.
I can't complain about the cost of car plugs though. Try buying Champion fine wire iridiums for an aircraft engine. They're $55 apiece and come two per cylinder. $300 for a plug change hurts no matter how you cut it.
Waste spark using standard plugs has been around forever.
The Toyota 3.4L V6 uses three dual wire coils in a waste spark configuration without platimum plugs. They use cheap ND or NGK standard plugs. The service interval is 30K miles to maintain the emissions warranty but I've run mine 60K without problems.
The 1969 Honda 750 4 cylinder motorcycles also used a pair of dual wire coils in a waste spark configuration as have most of the 4 cylinder models since. 4 cylinder bikes, through the 70's and early 80's, even had points. The ignitions on those old bikes were horrible, but it was weak coil output that was the problem, not the configuration with standard plugs...
The Toyota 3.4L V6 uses three dual wire coils in a waste spark configuration without platimum plugs. They use cheap ND or NGK standard plugs. The service interval is 30K miles to maintain the emissions warranty but I've run mine 60K without problems.
The 1969 Honda 750 4 cylinder motorcycles also used a pair of dual wire coils in a waste spark configuration as have most of the 4 cylinder models since. 4 cylinder bikes, through the 70's and early 80's, even had points. The ignitions on those old bikes were horrible, but it was weak coil output that was the problem, not the configuration with standard plugs...
Maybe someone can explain what the advantages of double-platinum vs. single-platinum plugs are.
By the way, the Ford ignition system that came with non-platinum plugs is most certainly a waste-spark system. The specified Motorcraft plug for the 1991 Ford Escort with DIS is "AGSF34CF4 [Copper] .054 Gap".
By the way, the Ford ignition system that came with non-platinum plugs is most certainly a waste-spark system. The specified Motorcraft plug for the 1991 Ford Escort with DIS is "AGSF34CF4 [Copper] .054 Gap".
The Ford, and probably other systems used reverse polarity on every other cylinder, so the ground electrode needs to be platinum on those systems if they are to last 100,000 miles.
When Ford used standard plugs with distributorless ignitions, like on my 1991 4.0 Ranger, the ground electrodes would not last very long.
Some Toyota 3.4 engines used a dual ground electrode copper plug to help extend the life. Those plugs are not particularly cheap.
When Ford used standard plugs with distributorless ignitions, like on my 1991 4.0 Ranger, the ground electrodes would not last very long.
Some Toyota 3.4 engines used a dual ground electrode copper plug to help extend the life. Those plugs are not particularly cheap.
- Status
- Not open for further replies.
Similar threads
- Replies
- 24
- Views
- 819
- Replies
- 73
- Views
- 3K
- Replies
- 14
- Views
- 2K
- Replies
- 4
- Views
- 288