I have a 2002 Tahoe 5.3L flex fuel. Per the owner's manual and sticker on the intake box, the recommend spark plug gap is .060". However, when I look up the ACDelco spark plug for that year/engine, it pulls up plugs gapped at .040". I know GM changed to .040" around 2004, but I'm having trouble figuring out why. Did they do it to consolidate inventory with one plug for all applications? Were they having coil/ignitions failures from the wider gap putting extra stress on the ignition system? The plugs I have in it now are NGK V-power TR55 gapped at .060" and they run fine. Idle is smooth, starts easy, and no misfires, even when towing. Is there any advantage to going to the narrower .040" gap plugs on a low rpm daily driver?
I'm not as versed in ideal plug gap for engines that see low cylinder pressure and low rpm. Most of the plugs I deal with in racing engines are .010-.025".
My understanding of this is a wider gap helps with low cylinder pressure, less turbulence, and leaner air/fuel mixtures. This makes the .060" gap seem ideal for fuel economy. Why did GM move to .040"?
I'm not as versed in ideal plug gap for engines that see low cylinder pressure and low rpm. Most of the plugs I deal with in racing engines are .010-.025".
My understanding of this is a wider gap helps with low cylinder pressure, less turbulence, and leaner air/fuel mixtures. This makes the .060" gap seem ideal for fuel economy. Why did GM move to .040"?