Whats Spark Plug Gapping?

[Ravrex]

Could someone enlighten me on the above mentioned. If this is done to save the plugs and extend their lives, why not simply just change new ones at new oil intervals?

[Yeobh]

Even new park plugs you need to check the gap. Without the right gap size, you will not be able to get the best spark.

[Elfenstar]

Taken from www.ngk.co.uk

 

Always set the spark plug to the engine manufacturer's specified gap setting. A gap that is too small means that the spark duration will be very quick and the spark will be thin and weak. The consequences of this may be bad starting and high exhaust emission levels. This will result in an increase in fuel consumption. If the gap is set too large, the ignition system will not be able to cope with the demands and a misfire situation will occur. Some wide gap spark plugs have a longer ground electrode to accommodate a wide gap setting. These must be used where specified, as opening up a standard plug to a wider gap setting may result in the electrodes not running parallel to each other. This could result in abnormal and premature electrode wear.

[Ravrex]

Thanks for the replies. Didn't know new spark plugs needed gap adjustment. Even those stock spark plugs provided by the car manufacturer themselves for the specific engines?

[Elfenstar]

Some sparkplugs come pre-gapped. For those you do not need to re-gap them unless the gap you require is different.

[Ravrex]

That was what i presumed as i just did my servicing today. Thanks for your reply!

[Yeobh]

Gapping by machine during production , the accuracy is only so so. If you want the best sparks then check and if necessary regap them.

Ask any mechanics and he will just tell you that checking the spark plug gap is not neccessary nowadays as the engine is comptuerised and therefore can take care of the the difference in spark output.

Many of them in the auto service trade still believe that all cars have a smart computer and thier time is running out.

[Elfenstar]

I've checked the NGK plugs and thus far most have been either exactly on the dot and those that are not are 0.05mm smaller. Still within OEM specs.

 

If you go cheaper then as i always say, you get what you pay for.