C55 spark plugs
Thread Starter
Member
Joined: Feb 2009
Posts: 180
Likes: 13
From: Cave Creek, AZ
2012 Mercedes S63 P30, 2015 Mercedes GL550, 2009 BMW 650i Convertible
C55 spark plugs
Yes, I did a search but didn't see anything for the C55, only the C32. My question is, how many miles are the stock C55 plugs really good for? I know they're platinum, which they say are good for ~100k miles, but I've always been a proponent of changing platinum plugs at no more than 50k, just for the sake of performance and efficiency.
My C55 has ~56k miles, and I'd just be using aftermarket platinum replacements (Autolite, NGK, etc.). I really see no benefit to spending more than $3/plug on an N/A car.
And is there any benefit to replacing the wires, assuming they're not damaged?
Thanks for any help!
Bill
My C55 has ~56k miles, and I'd just be using aftermarket platinum replacements (Autolite, NGK, etc.). I really see no benefit to spending more than $3/plug on an N/A car.
And is there any benefit to replacing the wires, assuming they're not damaged?
Thanks for any help!
Bill
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Joined: Nov 2008
Posts: 844
Likes: 1
I DON'T COME HERE ANYMORE
Wires help for a more consistant spark with less interferance (at higher RPM-you may notice a small amount of mis-fire from older/worn plugs, or plugs that are too hot for the car) best bet is to pull a back bank plug and see what it looks like-if its nasty-swap them out!
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Joined: Feb 2006
Posts: 6,213
Likes: 8
LET C32 2002
Yes, I did a search but didn't see anything for the C55, only the C32. My question is, how many miles are the stock C55 plugs really good for? I know they're platinum, which they say are good for ~100k miles, but I've always been a proponent of changing platinum plugs at no more than 50k, just for the sake of performance and efficiency.
My C55 has ~56k miles, and I'd just be using aftermarket platinum replacements (Autolite, NGK, etc.). I really see no benefit to spending more than $3/plug on an N/A car.
And is there any benefit to replacing the wires, assuming they're not damaged?
Thanks for any help!
Bill
My C55 has ~56k miles, and I'd just be using aftermarket platinum replacements (Autolite, NGK, etc.). I really see no benefit to spending more than $3/plug on an N/A car.
And is there any benefit to replacing the wires, assuming they're not damaged?
Thanks for any help!
Bill
Former Vendor of MBWorld
Joined: Jan 2007
Posts: 3,193
Likes: 3
From: Glendale Arizona
C55,SL55,C63
Remember you need 16 spark plugs for your C55. There will always be the debate on what spark plugs to get. I would just keep it simple and stick with the stock NGK plug and maybe just go one step colder. I sat for a while debating on what kind of plugs to get NGK, Denso, bla bla bla. I decided to go with a NGK OEM style plug, Only because it is supported well in my local area. I think thats the most important thing... IF a plug craps out getting one wont be hard.
expect to pay $7-8 dollars a plug for a good well respected plug.
expect to pay $7-8 dollars a plug for a good well respected plug.
Former Vendor of MBWorld
Joined: Jan 2007
Posts: 3,193
Likes: 3
From: Glendale Arizona
C55,SL55,C63
Just seen you are in AZ,... My plugs were on there last leg at 35,000 miles, when they were changed they were a rusty red/brown color from the crap fuel we get out here in AZ... Change your plugs.
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Thread Starter
Member
Joined: Feb 2009
Posts: 180
Likes: 13
From: Cave Creek, AZ
2012 Mercedes S63 P30, 2015 Mercedes GL550, 2009 BMW 650i Convertible
I'll most likely use inexpensive double-platinum plugs ($4 Autolites, NGKs, etc.) and not anything like iridiums, as I just don't believe I'll realize any cost/performance benefit. I just want the longevity of the platinum.
I owned a high-performance shop in NorCal for almost eight years, specializing in Mustangs and Vipers, and in all the high-hp cars we built, we used standard, cheapie plugs to make the most power. Platinum offers zero performance benefit, only longevity, and if you're hard on your plugs (i.e. a blown car, nitrous, etc.), they should be changed every 10k-20k miles anyway, so no sense in spending more than $2 a plug, really.
As well, we didn't have any luck with Iridiums on blower cars. Even with a high-output ignition like a Crane HI-6, any boost higher than 10psi would blow that fine-tipped spark out. We always relied on $2 Motorcraft, Autolite, or Champion plugs, even on cars making 650hp+ at the wheels. They consistently made the most reliable and consistent power.
Bill
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Member
Joined: Jan 2008
Posts: 197
Likes: 0
From: Houston, TX
2005 C55 AMG
Just as a point of reference, I purchased NGK copper plugs for my C55 soon after I bought the car. I've always believed in getting better performance out of a good copper plug rather than the longevity of a platinum or iridium plug. However, everything I had owned previous to the C55 made for a relatively easy plug swap job. Clearly that's not the case on the C55, and it also has 16 plugs to deal with.
When I pulled a couple of my stock NGK Iridiums out at 55k miles, I was very surprised to see the gap was still holding at the recommended .044. I was completely planning to replace all my plugs until I measured the two I took out, and realized there was no need to do it yet. Now that I have 67k miles on the car, I may check them again to see if it has changed at all over the course of a year. If so, I agree with what Billapex said above, in that you don't have to spend $16 per plug to get the Iridiums if all you're looking for is better performance. Cheap Autolite or NGK copper plugs will provide a better overall burn.
However, if you're not wanting to do the job again for 50k+ miles, then you'd want to at least go with a good platinum, which can be purchased starting at about $2.49 per plug on average.
When I pulled a couple of my stock NGK Iridiums out at 55k miles, I was very surprised to see the gap was still holding at the recommended .044. I was completely planning to replace all my plugs until I measured the two I took out, and realized there was no need to do it yet. Now that I have 67k miles on the car, I may check them again to see if it has changed at all over the course of a year. If so, I agree with what Billapex said above, in that you don't have to spend $16 per plug to get the Iridiums if all you're looking for is better performance. Cheap Autolite or NGK copper plugs will provide a better overall burn.
However, if you're not wanting to do the job again for 50k+ miles, then you'd want to at least go with a good platinum, which can be purchased starting at about $2.49 per plug on average.
Junior Member
Joined: Apr 2012
Posts: 17
Likes: 1
From: Cumming, GA
2009 ML63 AMG
Should I replace spark plugs on C55 AMG at 119k miles IF...
My wife bought a 2005 C55 AMG in March 2012 with about 105k miles on it.
She now has about 119k miles.
She drives it like a granny and recently boasted of a trip from Birmingham, AL to Atlanta, GA averaging 23 mpg !
If the car runs strong (when I drive it) and it is averaging between 17 and 18 mpg around town and gets 20 to 23 mpg on the highway...should I
1) Have a plug bank pulled to inspect the plugs (for potential replacement) ?
2) Just go ahead and drive on!
3) Change them and HOW?
Myself with the proper tools and moral support ? OR
Just pay about $250 labor with my MB specialist plus $8/9 bucks a plug on Amazon?
Like many others, I am on the fence about intervals / performance / preventative maintenance / over doing it when unnecessary
Thanks
She now has about 119k miles.
She drives it like a granny and recently boasted of a trip from Birmingham, AL to Atlanta, GA averaging 23 mpg !
If the car runs strong (when I drive it) and it is averaging between 17 and 18 mpg around town and gets 20 to 23 mpg on the highway...should I
1) Have a plug bank pulled to inspect the plugs (for potential replacement) ?
2) Just go ahead and drive on!
3) Change them and HOW?
Myself with the proper tools and moral support ? OR
Just pay about $250 labor with my MB specialist plus $8/9 bucks a plug on Amazon?
Like many others, I am on the fence about intervals / performance / preventative maintenance / over doing it when unnecessary
Thanks
MBWorld Fanatic!
Joined: Feb 2006
Posts: 6,213
Likes: 8
LET C32 2002
My wife bought a 2005 C55 AMG in March 2012 with about 105k miles on it.
She now has about 119k miles.
She drives it like a granny and recently boasted of a trip from Birmingham, AL to Atlanta, GA averaging 23 mpg !
If the car runs strong (when I drive it) and it is averaging between 17 and 18 mpg around town and gets 20 to 23 mpg on the highway...should I
1) Have a plug bank pulled to inspect the plugs (for potential replacement) ?
2) Just go ahead and drive on!
3) Change them and HOW?
Myself with the proper tools and moral support ? OR
Just pay about $250 labor with my MB specialist plus $8/9 bucks a plug on Amazon?
Like many others, I am on the fence about intervals / performance / preventative maintenance / over doing it when unnecessary
Thanks
She now has about 119k miles.
She drives it like a granny and recently boasted of a trip from Birmingham, AL to Atlanta, GA averaging 23 mpg !
If the car runs strong (when I drive it) and it is averaging between 17 and 18 mpg around town and gets 20 to 23 mpg on the highway...should I
1) Have a plug bank pulled to inspect the plugs (for potential replacement) ?
2) Just go ahead and drive on!
3) Change them and HOW?
Myself with the proper tools and moral support ? OR
Just pay about $250 labor with my MB specialist plus $8/9 bucks a plug on Amazon?
Like many others, I am on the fence about intervals / performance / preventative maintenance / over doing it when unnecessary
Thanks
Junior Member
Joined: Oct 2012
Posts: 70
Likes: 1
'07 CLS 63, '91 E34 M5 Dinan Stroker
C55 Plugs & Wires Changed
I'm bumping an old thread, but I just did my plugs and wires yesterday after 84K original miles on the old plugs and wires. I went with the OEM NGK Laser Iridium IFR6D10 plugs and Bosch wire set. The plugs were not horrible looking and the head was very clean - A good sign.
While in there as a preemptive measure we also replaced both valve covers, the CPS, ambient temp sensor and replaced a broken fog light. I haven't done much DIY on the car but this is something I will do on my own next time, even though that will be a long time away. Attached are some pictures of the head and plugs at 84K miles.
While in there as a preemptive measure we also replaced both valve covers, the CPS, ambient temp sensor and replaced a broken fog light. I haven't done much DIY on the car but this is something I will do on my own next time, even though that will be a long time away. Attached are some pictures of the head and plugs at 84K miles.
