What is the normal life of plugs

[Martec]

I've been using NGK spark plugs BP6ES for some time but only got approx 3000 miles before minor missing could be felt at low revs, new plugs cured it for another 3000 miles.

With an ECU to give a better map for LPG I've changed to BPR6ES.

My question is '6' the best heat range for LPG?

And is the extra cost of Iridium plugs worth it in longevity?

Brian

[Gilbertd]

The R signifies that the have a built-in resistor, so changing from BP6ES to BPR6ES will make no difference. BPR6ES is the standard plug for my Range Rovers and I've fitted BPR6EIX Iridium equivalents as my Sabb did over 40,000 miles on a set of NGK Iridiums. Not done enough miles in either of them yet to see if they last as long, but most people reckon on 50,000 miles plus. If you earch eBay, you'll find a couple of suppliers doing them for around £4.50 each compared to the £8 each that my local motor factors wanted.

[pjpj]

If you are using single electrode copper plugs, you could try closing the gap 0.1 - 0.2mm to provide a stronger spark for the LPG to ignite.

As for the longevity, each car is different but I have to replace copper plugs every 12-15,000 miles.

[mat_fenwick]

The R signifies that the have a built-in resistor

I remember when I was young(er) and (more) naive, being told by a guy in Halfords that the R stood for 'Racing'. Imagine my disappointment when after I excitedly fitted them, my car did not instantly turn into a fire breathing performance machine...

[Gilbertd]

The unfortunate thing is that the guy in Halfords probably thought he was right. Could be worse though. I went into my local Maplins a couple of years ago and asked for the cheapest satnav they had that covered all of Europe (long story but I needed it there and then). I was handed a basic TomTom that covered UK and Eire. When I pointed out that I needed all of Europe I was told that Eire was just another name for Europe......

[redzed]

My brother witnessed a guy asking for some 'rubbing compost' in our local car shop instead of the usual 'rubbing compound'.

I was in Sainsbury's quite a while ago and heard a middle aged gentleman telling his wife how much cheaper the tea bags were in Kwik-Fit...think he meant to say Kwik Save.