Hello. I recently changed the spark plugs on my 1989 260e with around 135,000miles and out of curiosity I checked the gap on the old plugs. I was quite surprised to find that almost all six of them had gaps around .052 and some upwards of .056. The new plugs were ordered from FastLane and I left them at the pre-gapped .032. Anyone know what the deal is with the huge gap on the old ones? Could that have been hurting performance significantly, and should I increase the gap on the new ones a little? The engine seemed to rumble a little just at idle with the old ones and still does a little with the new ones.
Second question - is it about time to replace the ignition wires? As far as I know, they are roughly 13years old with 135,000miles on them. Will replacing the wires have any positive effect on performance? I think I can get a set of the wires on eBay for around $80. Thanks for any help/info!