Why does the Engine have 2 spark plugs per cylinder?
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2005 S500 Designo
Why does the Engine have 2 spark plugs per cylinder?
Seriously, why?
Someone asked me and I thought I knew, but the more I thought about it, the more the reason escaped me. Anyone have any idea?
Someone asked me and I thought I knew, but the more I thought about it, the more the reason escaped me. Anyone have any idea?
Thread Starter
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2005 S500 Designo
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From: North Carolina
2003 S500 - Toyota Corolla (in the rain)
"Supposedly" it makes the engine run more efficient. The idea is that twin flames will more efficiently use all the fuel injected into the cylinders to improve performance and reduce fuel use. Bottom line, it is really designed to cost more to service.
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From: Sidney, BC
2009 SLK55 AMG. & 2022 GLA250 4Matic
2 plugs
I have never had a coil go in any car and do not see it as cynically as some here.
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2005 S500 Designo
So I did a little research on Wikipedia and other websites.
https://en.wikipedia.org/wiki/Dual_ignition
Wikipedia seems to be particularly happy about dual-spark ignition claiming an up to 5% increase in torque and 10% improvement in fuel consumption.
10% is a lot, and it would manifest itself in the life of the car, so I think I'm going to run the numbers.
For fairness let's assume a 5% increase in fuel efficiency and completely ignore the increased performance.
Assuming an average fuel consumption of 25mpg, without dual spark ignition we would get 23.8 mpg on average.
Over 100,000 miles the savings would be over 200 gallons of fuel.
At a fuel price of $3/gallon that's $600.
Based off these calculations it's not worth the added coil packs, wires, and spark plugs. However at 10% efficiency, it would be close to $1200 in savings, and if European fuel prices were considered (generously $6/gallon) that would come out to $2400 in savings which is potentially significant, and that's ignoring the increase in performance.
https://en.wikipedia.org/wiki/Dual_ignition
Wikipedia seems to be particularly happy about dual-spark ignition claiming an up to 5% increase in torque and 10% improvement in fuel consumption.
10% is a lot, and it would manifest itself in the life of the car, so I think I'm going to run the numbers.
For fairness let's assume a 5% increase in fuel efficiency and completely ignore the increased performance.
Assuming an average fuel consumption of 25mpg, without dual spark ignition we would get 23.8 mpg on average.
Over 100,000 miles the savings would be over 200 gallons of fuel.
At a fuel price of $3/gallon that's $600.
Based off these calculations it's not worth the added coil packs, wires, and spark plugs. However at 10% efficiency, it would be close to $1200 in savings, and if European fuel prices were considered (generously $6/gallon) that would come out to $2400 in savings which is potentially significant, and that's ignoring the increase in performance.
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S55 AMG
So I did a little research on Wikipedia and other websites.
https://en.wikipedia.org/wiki/Dual_ignition
Wikipedia seems to be particularly happy about dual-spark ignition claiming an up to 5% increase in torque and 10% improvement in fuel consumption.
10% is a lot, and it would manifest itself in the life of the car, so I think I'm going to run the numbers.
For fairness let's assume a 5% increase in fuel efficiency and completely ignore the increased performance.
Assuming an average fuel consumption of 25mpg, without dual spark ignition we would get 23.8 mpg on average.
Over 100,000 miles the savings would be over 200 gallons of fuel.
At a fuel price of $3/gallon that's $600.
Based off these calculations it's not worth the added coil packs, wires, and spark plugs. However at 10% efficiency, it would be close to $1200 in savings, and if European fuel prices were considered (generously $6/gallon) that would come out to $2400 in savings which is potentially significant, and that's ignoring the increase in performance.
https://en.wikipedia.org/wiki/Dual_ignition
Wikipedia seems to be particularly happy about dual-spark ignition claiming an up to 5% increase in torque and 10% improvement in fuel consumption.
10% is a lot, and it would manifest itself in the life of the car, so I think I'm going to run the numbers.
For fairness let's assume a 5% increase in fuel efficiency and completely ignore the increased performance.
Assuming an average fuel consumption of 25mpg, without dual spark ignition we would get 23.8 mpg on average.
Over 100,000 miles the savings would be over 200 gallons of fuel.
At a fuel price of $3/gallon that's $600.
Based off these calculations it's not worth the added coil packs, wires, and spark plugs. However at 10% efficiency, it would be close to $1200 in savings, and if European fuel prices were considered (generously $6/gallon) that would come out to $2400 in savings which is potentially significant, and that's ignoring the increase in performance.
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2005 S500 Designo
Mercedes just loves to use that stuff as an excuse. If someone has enough money to buy a 12 cylinder car, will they really care about the mpg? The answer is no. Mercedes knows that their cars depreciate like crap, so they have to make everything over-complicated and have their cars constantly in need of repair and service. This will make people like me who bought an S600 for 1/10 of the original price still have to pay a crap ton of money just to keep the car running.
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MBWorld Fanatic!
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From: North Carolina
2003 S500 - Toyota Corolla (in the rain)
No doubt these cars are over engineered. The electronics alone can be a complete nightmare.
Don't even think about the cost of purchasing parts and service from the dealer.
Don't even think about the cost of purchasing parts and service from the dealer.
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From: Montreal, Quebec
2009 E350 4M Avantgarde;mistress 2002 S600; wife 2014 C300 4M
use of 2 plugs
the design is that the engine controller measures the ionization of the gas in the cylinder AFTER firing, and adjusts accordingly (adaptation).
Also, 2 plugs make sure the cylinder fires even with one plug dead (redundancy).
I agree it is overkill, but, the gas milage is phenomenal.
Also, 2 plugs make sure the cylinder fires even with one plug dead (redundancy).
I agree it is overkill, but, the gas milage is phenomenal.
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From: CALIFORNIA, UNITED STATES
2003 S430, 2014 E350
Mercedes just loves to use that stuff as an excuse. If someone has enough money to buy a 12 cylinder car, will they really care about the mpg? The answer is no. Mercedes knows that their cars depreciate like crap, so they have to make everything over-complicated and have their cars constantly in need of repair and service. This will make people like me who bought an S600 for 1/10 of the original price still have to pay a crap ton of money just to keep the car running.
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2005 S500 Designo
Okay, although the person who buys a 12 cylinder car, doesn't care about the MPG. Some of them actually do care about the environment. And Mercedes also gets a tax break if they make them good on gas, hence the cylinder deactivation on the M137. Or the S430 that actually gets really good MPG. It makes Mercedes look better as a company and it sure looks better on paper too. (not the repair bill of course)
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S55 AMG
Okay, although the person who buys a 12 cylinder car, doesn't care about the MPG. Some of them actually do care about the environment. And Mercedes also gets a tax break if they make them good on gas, hence the cylinder deactivation on the M137. Or the S430 that actually gets really good MPG. It makes Mercedes look better as a company and it sure looks better on paper too. (not the repair bill of course)
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From: CALIFORNIA, UNITED STATES
2003 S430, 2014 E350
The S class's power was falling behind its competitors. i.e BMW PORSCHE. They had no choice but to turbo the engines, and when you turbo the engine you cannot have half the banks not firing. Cylinder deactivation will kill the exhaust output by closing half the exhaust valves, and it won't be able to spin the turbines hard enough to make any useable boost. Even though the new S classes are all turboed, it doesn't affect Mercedes that much because the E classes are their best sellers. With all the new Hybrid and E-Drive cars. GLE, B-E Drive, S400 Hybrid etc. It really makes Mercedes "look" good.
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S55 AMG
The S class's power was falling behind its competitors. i.e BMW PORSCHE. They had no choice but to turbo the engines, and when you turbo the engine you cannot have half the banks not firing. Cylinder deactivation will kill the exhaust output by closing half the exhaust valves, and it won't be able to spin the turbines hard enough to make any useable boost. Even though the new S classes are all turboed, it doesn't affect Mercedes that much because the E classes are their best sellers. With all the new Hybrid and E-Drive cars. GLE, B-E Drive, S400 Hybrid etc. It really makes Mercedes "look" good.
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2005 S500 Designo
Oh it makes sense now. One more thing, I feel like I need to mention this: I was driving the car for a few weeks with only half the engine running since the coil pack went bad for that side. I thought it wouldn't be a problem since I was getting it fixed later that month, but maybe I'm stupid for driving a 12 cylinder car with only half the cylinders working? I still don't know if it did permanent damage to the car.
I don't think you did permanent damage, but it probably wasn't the smartest idea
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S55 AMG
It definitely wasn't the smartest idea but those coil packs are damn expensive and I needed a car to take me places. Also mine is the Twin Turbo which didn't even come with the deactivation, so I believe that just made the damage worse.
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From: Ball Ground, GA (N of Atlanta)
2003 S500 2007 GL450
I still find the split psyche on this forum fascinating...
"These are wonderful cars, the best ever made."
"These cars are over-engineered pieces of over-priced crap."
Often same person, different day...
"These are wonderful cars, the best ever made."
"These cars are over-engineered pieces of over-priced crap."
Often same person, different day...
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From: CALIFORNIA, UNITED STATES
2003 S430, 2014 E350
Well you have bought a Mercedes S class, an engineering marvel as you can say. (The new ones at least) If they think it's overpriced pieces of crap then just buy a Toyota. A shock costs a couple of Starbucks, and a Airmatic pump costs, what Airmatic?
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S55 AMG
It's funny that you can get a W220 S-Class for less money than a new Toyota.....
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From: CALIFORNIA, UNITED STATES
2003 S430, 2014 E350
The reason why you can get a w220 for less than a New Toyota is because of the Chrysler era. Everyone knows during the Chrysler era, Mercedes was bad, REALLY BAD. S classes are usually leased, because the owner wants the newest and the best. Most get CPOed and some get auctioned off. The earliest w220 is 16 years old, and it can't really be compared to new Toyotas.
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S55 AMG
The reason why you can get a w220 for less than a New Toyota is because of the Chrysler era. Everyone knows during the Chrysler era, Mercedes was bad, REALLY BAD. S classes are usually leased, because the owner wants the newest and the best. Most get CPOed and some get auctioned off. The earliest w220 is 16 years old, and it can't really be compared to new Toyotas.
