Review on NGK BKR8EIX IX Iridium Spark Plug/Single Piece - Revised for Enhanced SEO by Dave Giri

I've had good experiences with NGK in the past but not so much this time. The spark plugs worked fine for about 2 months (2800 miles per month) until under real load (50% gas; 35-40% with the A/C compressor on) my car started to sputter. I pulled the spark plugs and found that the .033" gap I had set widened to .040"+ on all 4 plugs. I reduced them to .030", which took a little over a month before the stuttering started again. I just re-draw them to find a gap greater than .040". I will replace them as soon as possible. For what it's worth, I experienced noticeably better low-end torque (a nice perk for a 4-cylinder car going uphill), while the spark plugs had a gap where I left them.