Manual says 100K Miles. I did mine at 50K. I would definetely do them around 80K or so. NGK is just fine. Look it up at www.sparkplugs.com for your particular vehicle. FFV vs non FFV may have different listing. I went with NGK Iridium IX. Paid about $8.50 or $9.00. Discount code exist quite often for 10% off.

 

do you like them??

 

I like them. did mine at 77k. purrs like a kitten.

 

im at 77 now might do them my next pay

 

They spark! And the engine runs great, just as it should. No difficulties ever reported with them.

 

I will be doing mine in the very near future. 104K on them right now, with about 20 of those K's towing 5000 lbs. It will be interesting to see if performance and MPG's improve much. Will post results.

 

Changed them last week, engine does seem smoother. Still have to see about MPG's. For the most part, plugs looked pretty good. Could have gone longer. All gaps were still .044". #3 had a bit of black soot on it and #4 was whiter than the rest. Replaced with same NGK PLFR5A-11 which they call their laser platinums. The back 2 plugs take as long to do as the front six.