OK take this for what it is worth, but I put ordinary Bosch Platinums into my D15B7 about 50,000 miles ago and haven't touched them since. No problems at all. I don't know if I would buy them again though.

 

Dont know if it's true or not, but I read on some forum that +4s run hotter and can warp the head.
Also, you do realize you don't get 4X the spark with those?..... just alot of marketing B.S.

 

Deff. major marketing BS ( Ive actually spoken to Bosch Reps about this at some of the retail/trade type shows Ive attended through my job) Personally I have used the +4s, as well as the regulars platinums, (in a 89 Probe GT, 89 Tbird SC, and 93 300zx Turbo) And period, point blank....they suck big sweaty donkey shlong. Dont like em, dont recommend em, and will flame you for getting them intentionally. lol. On a lighter note, for anything asian.... Nippondenso, or NGK is always the right way to go. Hell... if you wanna almost never replace em again, just put some NGK Iridiums in, and they last damn near 4ever.... had em in most of my cars(and ALL of my bikes), and put well over 90k on a few of em with out replacing them and then still looked great and the gap measured great.