Bosch Platinums suck?

I ran coppers in my LT1 for over 100k miles. Copper works fine with an opti.

You just have to change them more often, which is kinda a big pita on an lt1

curtis73 wrote: I agree that plugs tend to be brand-specific. No idea why, but its so true. They are an insulated conductor; doesn't seem to be any reason why a brand would work better in a certain vehicle. I can understand why mixing *types* of plugs could be an issue, like putting copper in where iridium was spec'd, or using a regular plug in a Toyota instead of the dual-electrode like BrokenYugo mentioned, but for cripes sake they're a conductor with ceramic around it that delivers 50,000 volts. Should be a no-brainer.

Some of the brand specific nature of spark plugs might be because of the less obvious effects caused by different materials and variations in designs.

Even though it's a simple conductor, it has capacitance, acts as an inductor, in addition to the simple resistance.

If these properties are too far from the oem specs it is possible that some of the energy can be reflected back to the distributor/coil or the effective resistance of the plug can be higher or lower than the oem plugs (and could vary with rpm).

Add in aftermarket wires,ignition components or poor block grounds and the changes can be amplified.

Or even more difficult to pinpoint, these properties can have different effects as rpm's increase and what may not be a problem at low rpm can suddenly show up at high rpm and vanish once the rpms drop.

In reply to BrokenYugo: Yeah, but that's an NGK plug, i'd use it without a second thought, the Bosch equivalent, no thanks.. If NGK came out with a "diamondfire mega 4 electrode plug" i'd give it a shot. Them E3 things, just no.. NGK makes quality plugs.

In reply to Hal: I as going to say that. Seems guys on the ZX2 sight ran into the same thing.

I never could get Bosch to work in my SAAB 96 either.

The Motercraft Platinums , Original in my ZX2/SR worked great for 98k miles when I sold the car.

06HHR wrote: In reply to BrokenYugo: Yeah, but that's an NGK plug, i'd use it without a second thought, the Bosch equivalent, no thanks.. If NGK came out with a "diamondfire mega 4 electrode plug" i'd give it a shot.

They do, in three and four electrode versions. Plugs that end with T are 3 electrode (like the BR8ET from an early RX-7), plugs that end with Q are four electrode (BR8EQ for example) and there are also surface-gap variants (BUR instead of BR)

I used to buy a set of four BR8ETs a month because they only lasted 3000mi and that is how much I was driving in 1998. I still remember the part number, 4221.