Spark Plug Comparison Test

[diamondlarry]

Author:diamondlarry
Publication:www.gassavers.org (http://www.gassavers.org)

When Fran reported on his experiment with spark plugs, I decided to round up my plug collection and do some tests of my own. I have acquired quite a collection of plugs in an attempt for mileage increases. I have a set of Splitfire Triple Platinum, Bosch Platinum +4, E3, Torque Master, and for control purposes a set of NGK standard plugs. It wasn't until Fran's report that I knew how to find out how effective each plug was at improving mileage and power.

The route I chose was a one mile stretch of a county road near my house. I also chose 50 mph as my testing speed. I crossed the starting point already at my test speed. At the end of the mile, I turned around at a small township firestation to go back to my starting point. To keep the conditions as constant as possible, when I turned around, I accelerated to 15-20 mph in 1 st gear then shifted into 3 rd gear and accelerated to 40 mph then shifted into 5 th gear to accelerate to my testing speed of 50 mph. At each acceleration, I pressed the gas pedal to 2/3-3/4 throttle. I did 5 runs for each of the 5 plugs. After the 5 th run for each plug, I did 5 acceleration runs to test for possible power increases. I did the acceleration run by cruising at 30 mph in 4 th gear and flooring the gas pedal. When the speed reached 35 mph, I started my stop watch and continued accelerating to 55 mph at which time I stopped the stopwatch. Below are my test results.

http://images6.theimagehosting.com/albums/3005/spark_plug.th.gif (http://images6.theimagehosting.com/albums/3005/spark_plug.gif[/IMG)
(click to zoom)


I took the highest and the lowest mpg and times and discarded them to come up with an average for each plug in each category. My tests indicate that the only significant increase was with the Splitfire Triple Platinum plugs. It also shows that mpg actually decreased with the E3, Torque Master, and Bosch Platinum +4 plugs. According to the Splitfire website, their plugs sell for $5.99/plug. My conclusion: While Splitfire Triple Platinum plugs do give slightly increased mileage, it may not be worth the added cost.

[chasgood]

I was just wondering if spark plug gap has any effect on mpg. Try your collection of plugs with a more narrow then wider gap and see what happens.

[diamondlarry]

I had thought of that but three of the 5 plugs I tested can't have their gaps changed; the gap is a part of the design of the plug. The three are the E3, Torquemaster, and Bosch Platinum +4. Fran Giroux has been after me to do a gap test on the others but I haven't had the time. I did see on http://www.lubedev.com/articles/ that the author in one of the articles suggests that running the gap .010 smaller would give better mileage. His reasoning was that the amperage would be higher which should be a hotter spark. It does sound like it makes sense though.

[wadak1234]

Larry what kind of vehicle did you use for you spark plug tests and how did you measure your gas mileage. Did you use something like a Scan-gauge or does your vehicle have a built in computer? I have been running spark plug tests in my 97 Dakota v6. I also have an after market ignition and I have been using a Scan gauge with my truck to check mileage averages. I found the Scan-gauge was off about 2 mpg on the high side. It does give you the option to compensate for that. I believe that now it gives me pretty accurate reading. I have tested the E3, Bosch Platinum +2, Autolite 3923's in 2 different configurations and I currently am running a set of Torque Masters that are a direct substitute for for the Autolite 3923s.
It seems to me that I have had the best results on mpg using the Autolite 3923's that I had side gapped. I currently running the Torque Masters and had them in for about 1500 miles. The truck runs well on them. I think plugs differences are minimized with the after market ignition.
By the way, I found a way to increase the gap on a set of E3's buy using drill bits to measure gap and using a Jewelers Flat Blade screw driver to gently pry open the gap. I wouldn't recommend this to anyone. I did ruin a brand new plug by doing this. I was able to sucessfully open the gap up a maximum of 15 thousands without messing up the other plugs. My truck started to ping on these. I think it's due the fact that they develop a much faster flame front than other spark plugs. I still waiting for the company that develops the E3 to come with an equivalent to the Autolite 3923-one range colder than stock to prevent pinging. So far the best average mpg for city driving I have achieved is 17.5 using the torque masters and about 18.5 with the side gapped Autolites. So far after my tests, I'm wondering if all the exotic expensive plug types are really woth it. Remember this is only my experience and I do have a complete MSD system. Your experienced may be different. I looking to increase my gas mileage any way I can. I have been doing this long before gas prices took the big jump due to Katrina.

[diamondlarry]

After I looked at the article for awhile I realized it doesn't say what vehicle I used. It is a 1997 Saturn SL 5-speed. I do own a Scanguage and that was how I measured the mileage. I have found that the Scanguage mileage can vary even without changing any of it's settings but overall it's pretty close once you get it calibrated.
I too have been looking for ways to increase mileage for a long time. I'm 42 and my quest for mileage came at around the time when I was 16 and had to start buying my own gas. Smiling

[Matt Timion]

After I looked at the article for awhile I realized it doesn't say what vehicle I used. It is a 1997 Saturn SL 5-speed. I do own a Scanguage and that was how I measured the mileage. I have found that the Scanguage mileage can vary even without changing any of it's settings but overall it's pretty close once you get it calibrated.
I too have been looking for ways to increase mileage for a long time. I'm 42 and my quest for mileage came at around the time when I was 16 and had to start buying my own gas. Smiling

A little off topic, but since you guys seem to be talking about the scangauge, let me ask about it. I understand that it's a OBDII toy, correct? Do you know of a OBDI equivilant?

[diamondlarry]

Unfortunately, no.

[TechGuy61]

I'd be interested to see your results with "side Gapped" plugs. You can find more information at this site about how to modify your stock plugs to get more complete combustion:

http://performanceunlimited.com/documents/plugsidegapping.html

I haven't tried this on my car yet but will soon. I'm currently experimenting with Acetone in the fuel. So far so good. I'm seeing better acceleration but haven't burned through my first tank yet so I can't comment on MPG yet.
http://www.lubedev.com/smartgas/additive.htm

[kickflipjr]

this is a good test diamondlarry. I just came accoss it.

[diamondlarry]

I'd be interested to see your results with "side Gapped" plugs. You can find more information at this site about how to modify your stock plugs to get more complete combustion:
http://performanceunlimited.c....html

I thought about that but I don't have a die grinder and I'm not sure I could do it very well with a hacksaw. Later this spring I may try comparing my Halo plugs to my Splitfires. That is if I don't lose my Splitfires by then. :D

[katman]

I thought about that but I don't have a die grinder and I'm not sure I could do it very well with a hacksaw. Later this spring I may try comparing my Halo plugs to my Splitfires. That is if I don't lose my Splitfires by then. :D

You can get one for about $20.00 at Harbor Freight. Harbor Freight is your friend!

[SVOboy]

Yeah, I need to get a dremel or something when I do my spark plug testing to speed up the grinding.

[vegasjetskier]

It seems to me that this might result in shorter plug life. By side gapping the plugs, a great deal of electrode material has been removed. The spark will now jump the gap to the corner of what's left of the electrode. As that material is eroded, the gap will get wider much faster since there is no other electrode material in proximity, as there was before the modification. I guess this won't matter much to those of us who change our plugs often. I'm the type that's like to "install 'em and forget 'em," though. :D

Patrick

I'd be interested to see your results with "side Gapped" plugs. You can find more information at this site about how to modify your stock plugs to get more complete combustion:

http://performanceunlimited.com/documents/plugsidegapping.html

I haven't tried this on my car yet but will soon. I'm currently experimenting with Acetone in the fuel. So far so good. I'm seeing better acceleration but haven't burned through my first tank yet so I can't comment on MPG yet.
http://www.lubedev.com/smartgas/additive.htm

[molecule]

a great site on spark plug technology
http://www.perma-tune.com/white-paper.html

predominant power comes from initial charge
all power after that moment follows the same path and is redundant with no affect on molecules in the chamber...

[JanGeo]

The only thing I can add is that by making the gap smaller it sparks sooner by a fraction of a second since the rising voltage spike jumps the gap a little easier thus at a lower voltage thus sooner. Also since the energy content of the coil is fixed and you reduced the voltage then it probably will spark for a longer period of time and not at a higher current.

[ZugyNA]

You can get one for about $20.00 at Harbor Freight. Harbor Freight is your friend!

I bought a little Dremel type tool with a bunch of bits and so forth for $10...works fine. Even has some spare brushes.

[JanGeo]

GOD that thing was a piece of junk compaired to a real dremel tool - most of the stones were out of balance and not centered on the shaft . Yeah it spins but jeeszzz stop it with your fingers.

[molecule]

lol...my friend ported his b18 head with one of those....lol

[cfg83]

diamondlarry -

(EDIT : I assume your test was with a Saturn S-Series)

I was looking at the E3 spark plug website today, and that led me to your spark plug test thread. Here is something I found on saturnfans regarding Saturn spark plug systems. It seems that Saturns have "waste spark" ignition systems :

Happy Bosch Platinum +4 Users ? (Or any Platinum Plugs)
http://www.saturnfans.com/forums/showpost.php?p=825729&postcount=8
NOTICE: Saturn fans; be advised about a potential problem using platnum type spark plugs installed in engines using the "waste spark" type of ignition system. Please be advised that any engine that uses the waste spark system will run BETTER on the STANDARD type of spark plug, NOT the platinum type. (this includes most (all?) Saturns and both my '98 and '99 SL-2 have this type) There is a scientific reason for this. It is because in a waste spark system, one half of all the spark plugs fire in REVERSE POLARITY. That is, the spark jumps FROM the SIDE electrode to the center electrode. (Normal polarity is when the spark jumps from the center electrode to the side electrode. That is one reason why spark plugs with high milage will develop a "dish" on the underside of the side electrode, where the spark, when it jumps from the center electrode will strike the bottom side of the side electrode and erode the metal and form a slight "dish" shape. This is one of the methods a spark plug will wear in a normal manner.) However, in a waste spark system one-half of the spark plugs are always firing in reverse polarity. This is because the high voltage ignition coil is connected in series with two spark plugs and the two plugs always fire simultaneously but are 360 degrees out of phase, i.e. one wire from an ignition coil is connected to the number one cylinder and the other wire from the same coil is connected to the number four cylinder. The same is true for the other coil except the other coil wires are connected to the number two and three cylinders. The number one and four and number two and three cylinders are always 360 degrees out of phase with each other. (This is the origin of the term "waste spark" because when one coil fires, only one spark plug ignites the fuel-air mixture and the other spark plug "wastes" its spark.) Now, the problem with the platinums is that the center electrode is very small and it is more difficult for the spark to to try to jump onto its "target" with a very small center electrode . The reason the standard design spark plugs will run better is that they have a much larger center electrode for the spark from the side electrode to discharge onto. This is why standard, i.e. Bosch "Super" or equivalent type plugs will run better in any engine using the waste spark ignition system. Engines with the coil over plug (COP) ignition system, (i.e. a seperate and dedicated coil for each cylinder) always run in normal polarity; so platinum spark plugs will work fine in these type ignition systems. Also, be aware that in order to use a waste spark ignition system, the engine must have an even number of cylinders. Five cylinder engines will always use a coil over plug (COP) system or a similar method with a dedicated ignition coil for each spark plug. - Sherrill

Right now I am using the Denso Iridiums with the tiny center electrodes, and I haven't had any real issues.

My question is, would your testing have been hampered by the Saturn's waste spark system? If yes, then the results wouldn't be comparable to cars with normal(?) COP (Coil Over Plug) spark ignition systems.

This might mean that for Saturns, the stock spark plugs are the best :

NGK 6953 V-Power Spark Plug
(Recommended for S series DOHC 1.9L, slightly cooler than the NGK5155)
Part Number: NGK6953

CarloSW2

[Red]

The logic doesn't make sense, that one plug fires normally while the corresponding plug fires in reverse? Whats the point?

The Jeep uses a "waste spark" ignition as well with the coils wired in parallel not in series like that thread seems to suggest and I've noticed no difference in wear or drivability when I switched from copper plugs to double platinums.

[cfg83]

Red -

The logic doesn't make sense, that one plug fires normally while the corresponding plug fires in reverse? Whats the point?

The Jeep uses a "waste spark" ignition as well with the coils wired in parallel not in series like that thread seems to suggest and I've noticed no difference in wear or drivability when I switched from copper plugs to double platinums.

I think this was a big debate over at saturnfans, but the "waste spark" argument seemed to prevail. I haven't experienced bad performance either, but my Densos start looking foul, I will swap some NGKs in and see what happens.

Just throwin' it out there,

CarloSW2

[hefeled]

I realize this is several months after the forum discussion, but I've recently been searching for new plug/products. I found an online source for HALO spark plugs. Apparently they've been around since the early 90's. Their design differs from that of a conventional plug in that instead of an "L" shaped electrode (or multiple ones on triple fires etc...) they have a circular "halo" which allows the combustion to shoot through instead of having what they term a quenching effect produced by the "L's." Have you read anything about them. Their website indicates increased performance in HP, mileage and especially emissions - but why wouldn't it?
Dan

[cfg83]

hefeled -

I realize this is several months after the forum discussion, but I've recently been searching for new plug/products. I found an online source for HALO spark plugs. Apparently they've been around since the early 90's. Their design differs from that of a conventional plug in that instead of an "L" shaped electrode (or multiple ones on triple fires etc...) they have a circular "halo" which allows the combustion to shoot through instead of having what they term a quenching effect produced by the "L's." Have you read anything about them. Their website indicates increased performance in HP, mileage and especially emissions - but why wouldn't it?
Dan

I don't know if they work, but here's two threads on Halo plugs :

Halo sparkplugs - 11-28-2005, 07:07 PM
http://www.gassavers.org/showthread.php?t=263

Halo Plugs - 08-31-2006, 10:56 PM
http://www.gassavers.org/showthread.php?t=1646

And here's some Halo's on ebay :

Halo Plug B-GR17YC-3 Save Gas/Fuel, Reduce Emissions!
http://cgi.ebay.com/ebaymotors/Halo-Plug-B-GR17YC-3-Save-Gas-Fuel-Reduce-Emissions_W0QQcmdZViewItemQQcategoryZ33693QQihZ020 QQitemZ300104325302QQrdZ1QQsspagenameZWD1V
... http://stores.ebay.com/Greenplugs

Here's the parent site, but they're not selling them anymore :

http://www.haloplug.com
November 1, 2007

We have decided to cease selling the Halo Spark Plug as of November 1, 2007. For now, you may check out www.lsgbrisk.com to consider purchasing.

Thanks to all our thousands of former customers.

Roger Gibson

CarloSW2

[ffvben]

just a sidetrack note: i always thought their was 2 spark plug sizes. the 08 sentra uses super tiny plugs, i think 14mm. i can't fit my pinky finger in the hole spark plug hole. dam now i got to buy a 3rd spark plug socket to add to my collection.