Spark Plug Gaps - Regular vs Platinum


DOCTORBILL
04-06-2008, 11:29 PM
I am using Bosch Platinum +2's in all my vehicles. I am not advocating the use of Bosch Plugs!
I just have always had good performance and mpg's with them.

Please - no nasty comments !

Suzuki Sport Sidekick ('97) - 1.8 Liter
Suzuki Esteem ('99) - 1.8 Liter
Geo Metro ('93) - 1.0 Liter - not installed yet
Jeep Cherokee ('91) - 4.0 Liter - not installed yet

I took the NGK plugs out of my Geo Metro yesterday at about 18,000 miles on
the plugs and was surprised to see the wear on them.

I had to close them down about 0.015 inch to put them back at 0.035 inch !

The electrodes were rounded and the rod tips were rounded.

Number 1 and 2 were white and clean - number three was clean but the cone was reddish colored. (?)

Here is my question.

If the spark gap is so important on a regular format spark plug, why is it that
these Platinum Plugs like Bosch don't need gapping?

http://img255.imageshack.us/img255/2954/regularsparkplug02ba5.jpg

Here is a close up image I took of the Bosch Platinum +2

http://img87.imageshack.us/img87/4518/bosch2sparkplug01ao2.jpg

Here is what Bosch says about this configuration:
"The spark of a Platinum+2 first travels over the surface of the insulator nose
and then arcs across the air gap to a ground electrode for a longer spark,
without increasing the voltage requirement. Plus, the yttrium alloy ground
electrodes help to reduce gap wear and oxidation, extending the service life
of the spark plug."

I know that the plug gap can control when the spark occurs - but that depends
on the shape of the electrodes.

Pointy can spark much sooner than blunt due to volt/sq inch air leakage.

My wife's Suzuki Sport Sidekick had really badly worn out regular plugs when
we bought it used recently.

I replaced the worn plugs (maybe 0.060 gap!) with Bosch Platinum +2's and
the vehicle has quite noticeable power improvement.
That probably would have happened with properly gapped regular plugs, too.

Just thought I would start a discussion of Regular vs Platinum Spark Plugs....

BTW - have any of you readers tried these new plugs advertized in various magazines?
They are about $25 each and have been around for about 6 years.

http://img212.imageshack.us/img212/3314/pulseplugadta2.jpg

http://www.pulstarplug.com/

The web site shows a "movie" of how this plug fires vs regular plugs.

DoctorBill

GM Line Rat
04-11-2008, 09:14 AM
I took the NGK plugs out of my Geo Metro yesterday at about 18,000 miles on
the plugs and was surprised to see the wear on them.

I had to close them down about 0.015 inch to put them back at 0.035 inch !

The electrodes were rounded and the rod tips were rounded.
DoctorBill

All 3 plugs were out by 0.015 ?......Hard to find this a coincidence Doc. I'd say the NGK Plugs were not gapped correctly before being installed the 1st time. 0.050 VS 0.035 is quite a bit off, and would also explain the wear and poor performance on the plugs. You did check the correct gap on the NGK Plugs before installing them.......Didn't you Doc? Never trust the gap from the factory on standard type plugs. Always check/Set for the correct gap according to the Car manufacturers specs before installing them.


Here is my question.

If the spark gap is so important on a regular format spark plug, why is it that
these Platinum Plugs like Bosch don't need gapping?

DoctorBill

1st, your dealing with 2 electrodes on the Bosch plugs VS 1 on a standard format plug. According to Bosch, these plugs produce a more powerfull spark across both electrodes and a more complete burn process in the cylinder....:rolleyes: Hence, just looking a both the NGK and the Bosch plugs, it easy to see why the bosch plugs dont require any gapping......It a totally different design.

DOCTORBILL
04-11-2008, 03:04 PM
Sure I gapped them!

The 'arm' on the No. two plug was rather soft and was thinner.

I had never seen plugs "wear" like those last ones did. (?)

I seem to have a little more power now - "seem" - hard to quantitate.

I was/am getting a crappy "about" 44 mpg during the winter cold weather.

I was getting an average of 49 mpg last summer after I did my infamous Head
and Rings job on this '93 3 cylinder Metro.

When the weather gets warmer here in Spokane, WA - I will see if the Bosch Platinum +2's
get any better than 49 mpg.

It is humerous - when you buy the Bosch Platinum +2's, you get a 5 year warrantee.

Most ludicrous! Against what? I have NEVER had a plug break or fall apart.

Wear?

If ANYONE has taken a Bosch Platinum plug back on warantee, I sure would like
them to reply to this thread and let us know what happened!

DoctorBill

lancekilgore
04-13-2008, 09:03 AM
I learned along time ago you never even try to gap the bosh style plugs because you will break the electrod wire and render the plug usless.

I do like bosh plugs but have found through time that some engines don't. some time back about 13 years I installed the bosch on my 95 and 94 1.0 geos and I lost 15 mpg with them reinstalled the reg plugs and got 45 mpg again.

just my two cents
Lance

302Z28
04-18-2008, 09:26 AM
Many years ago, when I began learning about cars, several old mechanics told me that a good rule of thumb is 0.001" of wear on the plugs per 1,000 miles. Of course, that was before platinum plugs and electronic ignition systems.
Thanks

dwendt1978
05-22-2008, 08:46 PM
Doc,

How have these plugs worked out so far? mpg's??
Bosch Platinums, right?

leonbentz
06-01-2008, 09:40 PM
It's nothing uncommon for plugs to wear a gap wider in these cars of today.
My Metro did and I had to regap them last week. My Nissan truck was also bad about wearing the gaps open. It seems to be a common thing. It's easy enough to believe that the quality of steel in the spark plugs has definately went south, since Grandpa was driving his '49 Plymouth. Newer and hotter ignition systems take their toll on the plugs.:smokin:

DOCTORBILL
06-01-2008, 11:14 PM
dwendt1978 - "How have these plugs worked out so far? mpg's??
Bosch Platinums, right?"

Yes - the Bosch Platinum 2's.

Last week, I filled my tank at COSTCO (God knows who's gas one gets!) and calculated
getting 49.1 mpg in weather anywhere from 40 to 70 F.

Not bad, hmmm?

Anyway - I got $1 rebates on eight Bosch Plugs also.

So I am happy about the Bosch Plugs.

It would be difficult to scientifically test different plugs because of the changes
in weather (temp and humidity), gasoline standards (??) and my driving habits.

"To each his own" - "Different strokes for different folks"

DoctorBill

MrPink
06-10-2008, 01:07 PM
I really like the NGK V-power plugs. Cheap, low resistance, can't beat 'em with a stick.

-Pink

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