I read in an auto maintenance book about 35 years ago that you should gap everything very uniform, because this will ensure the cylinders will all behave uniformly. in those days it was .03, and you had to use a wire gap, because the electrode is slightly curved. slightly narrower gap might fire slightly quicker, have a weaker spark, if the next cylinder is wider, it might fire slightly later, with a stronger spark, and possibly the computer cannot act that fast to compensate for this going on. that is why i always do my own gap, i insist the gap be just about right on spec, or at most .001 less , for instance if spec is .044, i will do them all at either .044 or .043 for instance .043 is 1.09 mm. that is about as tight as i would go for a spec of 1.1mm .044 is exactly 1.118 mm so if your gap is
1.09 or 1.11 that is probably good, but like i say, i would not accept plugs gapped like 1.15 1.05 etc - and if the hotter plug wears faster, this would be double jeopardy. i find it very hard or impossible to gap the very fine wire iridium with a wire gap tool, also i usually run iridium platinum, and I also BEND THE ELECTRODE to MAKE SURE THE PLATINUM AND IRIDIUM LINE UP. Feeler gauge is the only way to gap these new high tech plugs.
i have always done my spark plugs this way for 35 years now, and i have always been rewarded with a very smooth running engine.
It is not so hard to properly gap a plug, it just usually takes me 30 minutes for a set of four, or 45 minutes for a set of six. this is time well spent.
1.09 or 1.11 that is probably good, but like i say, i would not accept plugs gapped like 1.15 1.05 etc - and if the hotter plug wears faster, this would be double jeopardy. i find it very hard or impossible to gap the very fine wire iridium with a wire gap tool, also i usually run iridium platinum, and I also BEND THE ELECTRODE to MAKE SURE THE PLATINUM AND IRIDIUM LINE UP. Feeler gauge is the only way to gap these new high tech plugs.
i have always done my spark plugs this way for 35 years now, and i have always been rewarded with a very smooth running engine.
It is not so hard to properly gap a plug, it just usually takes me 30 minutes for a set of four, or 45 minutes for a set of six. this is time well spent.
