OEM Recommended NGK Spark Plug Part Number Change

Just bought NGK Iridium stock #5464 BKR5EIX-11 This is what AutoZone claims is for a 2007 GenII Prius... I've found some confirmation online, have yet to find confirmation on Prius Chat... NGK really doesn't need to change the numbers around again and again do they?

 

That plug would not be my first choice. While it will "fit" and will "work", I believe it will have a shorter service life compared to the correct NGK IFR5T11 plug. The correct iridium plug has a platinum disc attached to the ground electrode.

If you look at the NGK website you will see that NGK produces an Iridium OE plug model, which offers very long service life, and an Iridium "performance" plug model. The plug that you bought appears to be in the latter category.

 

Wow... Thanks Patrick... So grateful for your reply... More and more I'm thinking the best perk of being a Prius owner is the smart-folks on PriusChat.

Will both plugs give the same gas mileage?
Is the only difference being durability?
Cause knowing me I'll likely change my plugs out way sooner than 117K from now... I mean I've only had the car for 15K and I have endless fix up ideas for it... Most of all I still can't get over that spark plugs will last that long. What's next? Tires that never wear out?

 

Will both plugs give the same gas mileage? Yes
Is the only difference being durability? Yes. I haven't seen a specific durability claim for the performance Iridium plug, so my guess is that it may last 60K miles.

 

Thanks Patrick, Auto Zone said the plugs you recommend would be a special order and cost a couple bucks more than the ones I bought... And 60k miles on a set of plugs is probably good enough for me because I love working on my car and I'll likely have plenty of opportunities to replace plugs with the better ones down the road.

QUESTION: Auto Zone guy said recommended gap is .44 ? Is that ideal? I've had cars in the past that burned a little cleaner/slight MPG improvement when I made the gap bigger than recommended. Is that the case with this car too?

 

The correct spark gap spec is 1 mm to 1.1 mm. 0.044" is slightly more than 1.1 mm.

I usually set my plugs to the minimum 1 mm spec, under the assumption that the gap will grow over the plug service life.

 

Hi Prius Camper,
I also want to replace my 2008 Prius with new spark plugs. Can you please share your experience of using this type of performance spark plugs? I understand that they have a shorter life span than stock but if they provide better performance in terms of response gain or fuel efficiency, it might be worth considering.
I appreciate your comments.
thanks, RubberToe