Quote:
Originally Posted by BoxsterRS
My box is due for a Spark plug and oil change. I saw online some new bosch spark plugs that infuse iridium plus the plat +4 thingamajig. Is there any real difference from using these spark plugs from the oem ones ? What can I really expecto from these, I'm not expecting a single (1hp) from them but what difference do they make ?
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Hi,
Most of the rare metal sparkplugs out there are mostly a marketing gimmick. They will also last longer in some applications.
But, this is a false economy because you really don't want the plugs in for more than a couple years anyway. You really need to pull them to inspect them at least every 2 years and especially with the Boxster's Coilpak-on-plug, it's just as easy to swap them out when you do the inspection. Also, leaving them in for more than 2 years in an Aluminum Head can sometimes cause them to sieze.
A big factor in using OEM plugs is that the manufacturer (Porsche) set-up the taps in the Head so that the plugs will be properly indexed (electrode open to the desired Flamefront, as opposed to away from it) when properly torqued in place. If the plugs are not properly indexed (aftermarket plugs will be a crapshoot and usually off unless you go the Helicoil route and frankly it's not worth it), MPG may suffer mildly and the idle can be rough or hesitant.
A final issue with Aftermarket, or non-OEM plugs may be their Heat Range. There is no Industry Standard on this and each manufacturer's plugs have differing heat dispersion characteristics. While it's usually true that going from one heat rating to another increases or decreases the plugs heat dissapation by 85° - 100°F, it still doesn't guarantee that the plug from
manufacturer X has the same heat characteristics than those from
manufacturer Y, even though they share the same Heat Rating #. Unknowingly using plugs with an improper heat range can have effects which aren't noticed in the near term, but are potentially damaging nonetheless in the longterm.
There have been some reports of the Platinum tips breaking off on some of the earlier models causing damage to the pistons, heads and valves. If yours are spec'd as 4 prong, then go ahead. If not, best advice is to stick with OEM. Hope this helps...
Happy Motoring!... Jim'99