4 electrode spark plugs

It at least looks like I'm not alone then ! Apart from once, when it was very damp and cold, the car has started just fine, so perhaps there is something that is a bit marginal and the 4 point plugs make it much worse. Looks like they're a waste of money for sure.

I could understand Lodge Golden and Spitfires or whatever all those years ago being a con - but didn't expect the same from Bosch.

many vauxhalls cars have them as oem, so I know they must be very suitable for some applications. I always ran the sdI on NGK V series plugs (fine precious metal centre electrode) Denso plugs were absolutely terrible when they were put in Suzukis from the factory, we used to throw them out at the

VAGs used them too for a while.

Aren't they the plugs for the 100,000 miles service life used in the USA ??

David

lexus plugs are 63,000 service life and only have a single electrode, and they look like new when you change them!

Most likely they have a platinum electrode. They are not suitable for all cars, expensive as well.

Bosch have taken up the vacancy left by Lucas. They are willing to make anything down to the price the car maker is wiling to pay. It's easy to find out the quality of car electrical and electronic parts. If a pattern part can be had then the OEM item is crap. Though this isn't the case with Nissan 300ZX air flow meters. Fake ones are all over E-bay as the 500bhp resolution means they are in high demand for tuned Nissans that have a stock AFM that maxes at 250bhp.

Iridium are cheaper, have a fine wire electrode, work just as well and last just as long. Compared to a copper core plug, the initial cost may be 7x higher but as life is 10x they are cheaper per mile. If you aren't going to keep the car 42K miles (required to break even) maybe you failed to chose the right car in the first place.

Fine wire plugs are often required to get clean reliable combustion at idle. A misfire will dump raw un-burnt fuel on the cat, which will die shortly and be much more expensive to replace than the saving made buying gee-wiz plugs.

Except for a few engines that need surface discharge plugs, or fine wire NGK Iridium or Platinum, only NGK copper core plugs are worth buying. (ask any biker)

Interesting comment, the last Bosch plugs I bought (Bosch Super), all four had loose ceramics. I mean that they leaked, and I was able to turn the ceramic relative to the metal body by hand...

David

Quite possibly - they worked hand in glove in the '70s. The Lucas EFI on my SD1 uses mainly Bosch parts. Some alternators made by both companies had interchangeable parts.

But then Lucas made good stuff as well as rubbish. As you say, would make things for what the car makers were willing to pay. But they also made Rolls electrics too.

However, the four electrode Bosch plugs sell for a premium price.

indeed, when I ran a Suzuki shop we would not stock anything other than NGK, and we sold a great deal of their V series plugs too. When Suzuki briefly went to ND plugs we used to throw them away at the 500 mile service, otherwise the bikes would come back with misfire complaints, especially the two strokes.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Peter Hill saying something like:

Not sure I follow your logic, there.