ive not tried ngk car ones but on everything i have that came with them they dont last worth a crap, the stihl saw i bought wouldnt start less than 6 months after i bought it so i took it back and he just the plugs go. he put another one in it and that lasted another six months, i replaced it with a e3 and it start in half the time and that was like 4 or 5 years ago and that is still the same plug. same deal with my quads, snow blower, generator, lawn mower etc.. i put them in my cars now too and they out last my ownership of the car.
1998 Bonneville SSE
2007 Monte Carlo LT-KYB, Clarion, Polk audio, Kicker
1999 Yukon SLE-KYB, Air lift, Reese dual-cam, Tekonsha
1987 Firebird-355/th400-nothing stock