Has anyone tried using iridium spark plugs in place of normal plugs? I have been using Denso high power iridium plugs in my Peugeot 206-GTI for about a year now. I have also replaced my normal NGK plugs in my VW Passat VR6 with NGK iridium plugs, which are very good although not as high performace as the Denso's. The difference in improved performance is very significant for the Denso plugs and less significant for the NGK iridium. The Denso iridium power are really superlative plugs. The car seems to start much better, the idling noise level is significantly reduced and almost vibration free. Best of all for me, my 206 seems to have more revs. Acceleration is also better and surprisingly quieter. Fuel consumption has not gotten worse; in fact I think it is slightly better. If you have not tried iridium plugs, I stronly recommend these plugs. The Denso ones are very expensive and they come in 2 grades, one is power iridium plugs for high performance, and another long-life, for up to 200,000km usage. NGK sells a lower performance iridium plugs, but they are much cheaper.
I've started to Put BP Optimax Petrol in my car and it does actually work i have slashed off 0.4 secs of my 0-60 time in my Clio. It has a 97 Octane Rating over the regualar 95 it makes my car run smoother and i can get an extra 20 miles worth out of a full tank now.
Yes, they are starting to fit long-life iridium plugs in newer cars. However, there is a trade-off for such extended service life, and that is performance, which is noticeably slower than the iridium power plugs. But then the long-life iridium plugs can go on for 200,000km whereas the iridium power plugs last only 15,000-20,000km. The shorter life of the iridium power plugs is due to its tiny electrode, at 0.4mm in diameter. he long-life ones have an electrode diameter of 0.6-0.7mm. Platinum plugs have an electrode of 1.1mm diameter, and normal plugs have an electrode diameter of 2.5mm diameter. Believe me, there is a world of difference between normal plugs and platinum power plugs in performance. However, if you own a new Porsche, which comes with, I believe, Denso long-life plugs, you cannot change to the Denso iridium power plugs for better performance. The reason is that in the newer Porsches, you must remove the engine to get at the plugs, hence the standard factory fitting of long-life iridium plugs.
The leap from 95 octane to 98 octane is not in the same league as the leap from normal plugs to iridium power plugs. You have to try it to make another quantum leap.
I agree, provided the 98 octane gasoline costs the same as the 95 octane. If it costs more, it might be cheaper to switch over to iridium plugs and revert back to 95 octane. You can work it out, 20,000km for the service life of iridium power plugs vs the extra costs of 98 over 95 octane for 20,000km.
