What is the difference between these NGK Spark Plugs?

[jbillion]

W0133-1631655 NGK (OEM) Spark Plug PLFR5A11NGK PLFR5A-11 (OE = platinum). At this time, Bosch does not recommend a spark plug for this application. Production Date Range: To 12-2004 Yes $29.06 $12.71 W0133-1676088 NGK (OEM) Spark Plug LFR5AGP NGKNGK PLFR5A-11 (OE = platinum). At this time, Bosch does not recommend a spark plug for this application. Production Date Range: To 12-2004

[M45Runner]

W0133-1631655 NGK (OEM) Spark Plug PLFR5A11NGK PLFR5A-11 (OE = platinum). At this time, Bosch does not recommend a spark plug for this application. Production Date Range: To 12-2004 Yes $29.06 $12.71 W0133-1676088 NGK (OEM) Spark Plug LFR5AGP NGKNGK PLFR5A-11 (OE = platinum). At this time, Bosch does not recommend a spark plug for this application. Production Date Range: To 12-2004

The first one is platinum which will give you much longer life and the second one is copper. Copper ones are much cheaper, but in the long run, the platinum is a better deal.

[jbillion]

Thanks Kim,

I tried googleing the part numbers, but couldn't spot the difference. I'm definitely going with platinum.

[ken in az]

The iridium plugs are cheaper, and offer near the same life. Has anyone used them?

[EniGmA1987]

I havent used them, but I have heard that Iridium plugs are better than Platinum. Something about a more concentrated spark and able to ignite leaner mixtures.

[SteveTheTech]

The main difference is the LFR5AGP is not a dual platinum tipped plug. These plugs are not worth the risk, just source a good set of OE plugs (below). I have seen many negative side effects to different plugs.Sometimes the signs are not noticed like slightly decreased fuel economy as the result of increased resistance in the ignition circuit and the spark efficiency decrease could lead to a slightly rich running condition.

PLFR5A-11 on the right.

The large split electrode does not work to well on our cars. For some reason they like the single directed pulse in the center. You may have perfect results with either, they are great plugs in their own right. I can see the potential benefit of the

http://ngk.com/results_cross.a...0&y=0h ... .a...0&y=0

[szh]

BTW, separate off-topic comment - unrelated to the NGK question in this thread: please definitely avoid Bosch plugs with Nissan and Infiniti engines ... we have too many examples of people having serious problems with them.

I was reminded of this issue by the extract I saw in the original post in this thread that started with "Bosch does not recommend ..."

Z

[maxnix]

please definitely avoid Bosch plugs with Nissan and Infiniti engines ... we have too many examples of people having serious problems with them.

And Autolite, AC-Delco, i.e. - anything but NGK.

Got to this page and click on each plug type for construction differences

http://www.ngksparkplugs.com/p...e=nml

Unless you have a very compelling reason to use a different plug, always use OEM specified. The combustion chamber has been designed around them.