do expensive/premium spark plugs make a difference?

gilbert_and_sullivan

My 6 cyl Subaru running on LPG needs platinum/iridium NGK plugs, it takes 3 hours to change all 6, thats lying on your back shredding your hands in the tiny space between the rocker covers and the chassis rails with various combinations of extensions and ratchets, not a job for the faint hearted.

You could use a cheap standard plug and it would run ok, but the plug tips would burn out faster and it's not a job to repeat any sooner than you have to.

Joe_Horner

marlot wrote: »

62,500 for my car (Mazda MX-5 with a Zetec engine)

That's pretty extreme! Would have thought the biggest risk at that sort f interval would be the insulation breaking down rather than the tips but I guess they've improved ceramics as well!

gilbert_and_sullivan wrote: »

My 6 cyl Subaru running on LPG needs platinum/iridium NGK plugs, it takes 3 hours to change all 6, thats lying on your back shredding your hands in the tiny space between the rocker covers and the chassis rails with various combinations of extensions and ratchets, not a job for the faint hearted.

You could use a cheap standard plug and it would run ok, but the plug tips would burn out faster and it's not a job to repeat any sooner than you have to.

There's no need to make excuses or blame the designer for lazy car maintenance!!!! :rotfl:

gilbert_and_sullivan

Joe_Horner wrote: »

There's no need to make excuses or blame the designer for lazy car maintenance!!!! :rotfl:

It gives a year or so for your shredded hands to mend before you do it all again, thats' my excuse and i'm sticking to it..:p

To be fair the car is designed from scratch to be worked on and a pleasure to do so apart from those sparkies..

fivetide

Joe_Horner wrote: »

That's pretty extreme! Would have thought the biggest risk at that sort f interval would be the insulation breaking down rather than the tips but I guess they've improved ceramics as well!

Not new though. I had a Mitsubishi FTO (1995 model) and that had a six pot motor.


The front four plugs were regular ones and had the usual service intervals. The rear were a pita to get at and as a result Mitsubishi specced iridium plugs with a 60,000 mile service intervals. Two different types on one engine there. Never had any issues mind.

colino

Changing the plugs on many Jags is a relatively simple task (OK the inlet manifold is shifted to get to one bank on the V6s) but as the service interval for replacing the plugs is 70,000 miles for the V6 and 100,000 miles for the V8s, some middle aged cars have never had them done at all. Iridium plugs used to be crazy money, but at around £20 a plug, compared to a £8 a plug cheapo now, hardly worth the potential downgrade in performance and longevity.

Joe_Horner

fivetide wrote: »

Not new though. I had a Mitsubishi FTO (1995 model) and that had a six pot motor.
.

Not new??? '95 is practically showroom fresh around here!!