NGK spark plug update

Pursuant to the recent thread on Platium (sic) spark plugs, I decided to
visit a local auto parts emporium today. I knew I had seen NGK platinums
there for much less than $20 each at one point, so I thought I'd
investigate that more deeply.

Well, it seems that NGK has at least two price points for "platinum" plugs.
My usual installation for my car involves the ones designated BCPR6EP-11,
for $20 each. The ones I saw at the auto store today were BCPR6EGP ("G-
Power"), for $4.20 each.

The differences?
BCPR6EP-11:
- pregapped to 1.1mm
- platinum coating on BOTH live and ground electrodes

BCPR6EGP:
- NOT pregapped
- ground electrode looks cruder, omits platinum coating
- ground electrode has beveled edges

The plug body, insulator, and live electrode, all look identical between
the two.

I buy the BCPR6EP-11s at a local UAP outlet. They always have to order them
in. My EPA sticker specifies BCPR5E-11s for normal use, heat range 6 for
hot use.

The upshot of all this? Yes, you can find "platinum" plugs for $5 each, but
they are NOT the same as the $20 ones, regardless of whether you buy them
from the dealer or a jobber. Rip-off or not, you get what you pay for.

 

Is NGK$20 spark plug for the turbo charging ? Why do you have to
spend $20 for each spark plug ? I don't see the point unless $20 one s
must explode more energy to cylinder.

 

It may make sense when you have spark plugs that are difficult to
replace, such as with some transverse-mounted V6 or V8 engines, or
with any other engine where the plugs are hard to reach like rear
engine Porsches or boxer engines.

As I said before, if the original poster wants platinum spark
plugs, Denso is OEM spec and much, much cheaper in the aftermarket.
Denso doesn't have a line of "bargain" single platinum plugs that
I know of. I had a set go longer than 70K miles in my Integra
GS-R, and they probably could have gone much longer when I changed
them.

Here's a price list from Sunnyside Acura in Nashua, NH:

<http://www.acuraparts247.com/sunnyside/jsp/sp_srchrslts.jsp?sptype=Acura+Parts&pavalue=Tune+Up+Parts&spfeaturedprd=Spark+Plugs>

98079-5514N - PZFR5F-11 (NGK) - $14.32
98079-5515N - PKJ16CR-L11 (Denso) - $14.12

I recall Jason found that the NGK plugs in aftermarket sales were
nearly as much as the dealer. If he's in the US, find an AutoZone,
and they have those same Denso true double platinums for $6 each.
I don't know what the deal is, but there's no difference between
those plugs (with the same manufacturer's part #) sold at a dealer
or at an auto parts store.

 

my money is with iridium's. they're the closest thing i've found to the
gold/rhodium plugs that used to come in some turbo applications in the
80's. back then, i'd swapped out a set for a friend one time and took
the old ones home. being curious, i tried them in my old clunker and
found they'd start that thing much quicker in the crappiest weather &
made the car pull much better at low revs than before. good top end
too. on my civic, with the iridiums, i find it fires a little quicker
from cold and runs well across the board. add to that the fact that
they're rated for 100,000 miles & i think i have a low maintenance
winner! ymmv.

 

jim,
You raised a question that I did not think of: You mentioned that iridium
plugs are rated for 100,000. How miles are the platinum plugs rated for?
Jason

 

Depends on the manufacturer, but I think Honda specs 60K miles. What
does your owner's manual say? Personally I wouldn't want to keep
a plug in there that long without examining it for erosion.

 

I had a set of the aforementioned BCPR6EP-11s in for two years until last
year, which for me is 30,000 miles. The elctrode gap had eroded to 1.27mm
from 1.1mm. These plugs are in a cabinet in my basement. I keep them all
for reference.

I spend most of my time on the highway at or near 4,000 rpm, and have had
to go to the cooler plug to prevent overheating of the insulator.

 

I used to check them for erosion maybe every 15K miles or more if
I felt like it. Piece of cake with an inline 4, a locking extension,
and a torque wrench. I figured that removing and reinstalling them
would reduce the chance of the threads seizing.

Actually - last time I had plugs installed was at 90K miles with
the timing belt change of my '95 Integra GS-R. I didn't ask for
the service, got an apology, and I didn't have to pay for them. The
plugs were Denso, but were regapped from 1.1 mm to 1.3 by the
mechanic. I'd previously done the same thing (regap the 1.1 mm
versions) at about 70K miles. For whatever reason, no parts store
was able to get the 1.3mm version. I even called up Denso and they
said they'd be able to send me the 1.3 mm version as a swap. Never
happened, although I did get a Denso Spark Plugs cap. (???)

Do you swap plugs in the winter?

My Integra was stolen, recovered, and declared a total loss by my
insurance company. My current car is a Subaru, and the plugs
on a horizontally opposed engine are a PITA to get out. There
are no wires though. It's a distributorless ignition with a
coil pack connected to each plug. I'm not even going to touch
it until the recommended plug change interval.

 

No. Same plugs year-round. Since my driving is about 95% highway, always
above 60 mph, and always for at least a half hour at a time, any deposits
seem to be cooked off regularly regardless of ambient temperatures.

When I used the normally-specified BCPR5EP-11s, the insulator gets white
and bubbly. Ignition timing and fuel mixture are correct.

 

I bought a set of NGK Iridium IX spark plugs from eBay for $25, part
number ZFR5FIX-11 (2477). The sticker on my civic's engine called for
a 6 heat range but the NGK web site recommended a 5 for the IX plugs.

The engine is smoother at low rpms and much quieter at high rpm
highway cruise. No mileage change just quieter operation (better
spark?)

 

Tegger,
If a car owner has NGK platinum spark plugs in his car, how many miles
could he travel (mostly freeway driving) before he would have to change
the spark plugs?
Jason

 

(Jason) wrote in

I wondered that too. With two years and 30K on mine, there was no evidence
of any sort of performance problems. Mileage was unaffected.

After 60K, the gap would have widened to about 1.44mm. An increased gap
requires more voltage to make the spark jump, and increased voltage puts
extra strain on the coil. I don't know if the voltage would be increased
enough to eventually cause damage to the coil or not.

30K is all I'm willing to allow unless I get better info from somewhere.
Plugs are cheaper than coils.

 

Tegger,
Thanks--I get a major tune-up every 30,000 miles so will have them changed
or change them myself at that point in time. If you find any other data on
this subject, please post it.
Jason