How many miles do Platinum Spark Plugs last?
 

I've got a 99 Maxima SE with 60k on it. The dealer says my plugs don't need to be changed until 90k. I thought it was 60k. Anybody know when I should change my plugs?

100K. u can check them at 75-80k, but mine were excellent at 75k.

I changed mine for the hell of it @ 100k, and the originals were fine.

Our maintenance schedule calls for them to be replaced at 60K. That's when I had mine done and according to my mechanic, they needed changing. The 5th gens don't have to be changed until 100k. Not sure what the difference is with their plugs.

Replace them with NGK coppers. Platinum costs $8 per plug and lasts for 60k miles, copper costs $2 per plug and lasts for 30k miles. You do the math.

You need NGK part number BKR5E-11, they were $1.62 each at Advance Auto Parts.

I've changed 'em at 60k as well, although by the looks,I think they could gone quite a bit longer. But, I'd really be paranoid about leaving the stockers in there until 100k without at least taking them out checking condition, applying anti seize and putting back in around 50k. 100k is long time and those bad boys might have a heck of a time bustin' loose.

platinums are made for 60k, coppers are for 30k but cost 1/8th the price of plats and have a better spark...

I changed mine at 76K (GXE 98). The old plugs were in very good condition. They did not wear down at all. The gaps were the same as a new plug's. I am tempt to reuse the old plugs for the next change. Good idea?

is it possible to clean platinums? if so how?

Besides the lifetime of the platinums, do they perform better than the coppers?

nope...as said above coppers give a better spark...
lifetime (60k miles/change) is the only upper hand platinum has