I have had the Bosch Platinum 4+ plugs forever now, but I'm indifferent with the results. I have heard many people tell me they are crap and a waste of $ unless you have an import... for some reason no-one seems to recommend them for domestic cars. The guy at the local speedshop said to get a nice set of AC Delcos... then I thought Slit-Fire...

TPiS says this:
We have experienced over 9,000 RACING MILES on one set of Bosch Platinum Plugs. This is over 3 times what conventional plugs will do. Don't let the Split-Fire ads fool you - Bosch is the best.

...so now I'm lost.

 

ACs are the way to go. a search will bring up scads of info on the platinum vs. copper debate.

 

The bosch plugs themselves are excellent plugs, but the thing is, why would you pay such an outrageous price for spark plugs, and as you said it yourself; the gains are very marginal; if any. Stick with ACDelco plugs, they work just fine and the price is right.

 

ACDelco Rapidfires for sure!!

 

The standard Bosch platinums (single sidewire) may be fine but where the BS gets really thick is in the +4s - electricity flows to the path of least resistance so even if you have four sidewires there will still only be one spark. Either way, platinum is only a wear reducer and does bupkis for performance. If you do regular tune ups on your car then all you need is a plain old copper core plug. I recommend Autolites.

 

I was never happy with the Bosch Platinums. I've always been happy with the regular AC Delco's.

 

First: Bosch Platinums,result: fauling time after time.
Now: AC Rapidfire nr.2,result:no fauling!

 

i love my bosch platinums, especially since i only paid a dollar for 8. I wouldnt mess with the plus twos/fours but ive been using them for quite some time and i put over 70k on a set once and the car (now my uncles) still has them. They do foul easy in a motor that burns oil/runs rich but other then that i really like them.

 

I got Bosch plugs this spring when a garage tuned up my car then 2 weeks later a speedshop put on Edelbrock TES and the plugs would fit so they had to put Accel short plugs and threw out the brand new Bosch ones. So I wasted $24 for nothing could of a least gotten a lap dance

 

my z28 had a set of bosch platinums in it when i got it.. i don't like them one bit.

the car didn't run any different compared to the regular plain old ac delco plugs i put in... and once those plugs are fouled, they are fouled.

i prefer ac delco plugs.

 

nay for nawws.. lol..


no platinum plug is good for nitrous....

the +4s foul easier on engines that burn oil, because like someone said, the spark tends to only goto one or somtimes 2 points.... so the others tend to foul up..


just do a regular tuneup on your car and buy the cheapies... zero performance diff..

the reason platinum plugs were invented was because non-enthusiasts dont like tuneups... as the OEMs wanted to make the intervals longer between tuneups, they had to have a plug that lasted longer...

platinum doesnt wear nearly as fast.. therefore it can go for longer before it has to be replaced. thats it. no performance gain, its just a excuse to get a couple thousand more miles on the plug.

 

True, Bosch +4's are as well as being a waste of money and platinum plugs do nothing for performance, but platinum plugs last 5+ times longer than copper with absolutely no increase in spark gap over time. I've had no problem with regular Bosch Plats. in any car I've owned. I do regular tune ups, but one thing I don't regularly change (meaning: every tune-up) are the plugs. Don't need to. Same with oil- IMO, why run synthetic if you're going to change your oil every 3k.? Under normal driving conditions, even the cheapest of oils are not going to show significant breakdown after 3k. Then again, who here can say that they operate their car "normally" all of the time and never occasionally drive it hard or do a burnout every now and again...

 

Only thing I could think of is that the +4s may last longer in some engines and perform better when older because there are more electrodes to wear. Other than that, it's probably all bs. Especially the ads for those Split-Fires about making the spark shoot farther into the combustion chamber and such. Yeah right. And just because a plug fouls in your engine doesn't mean it's bad, it may just be the wrong plug for you.

I use regular bosch platinum. Never had a problem. I prefer them because they're shorter than most plugs and they don't come close to hitting my headers.

 

You forget that there is still only one center electrode that wears also.

 

You got it rezinn!

Bosch regular platinums are EXCELLENT plugs. Been running mine for 2 years now, NO problems! Fit around my Hooker Shorties perfectly. MUCH less expensive in the long run

Of course, there are those who just love changing spark plugs, those pathetic lost souls :nono:

And the platinum plugs burn hotter than regular plugs, that's a main reason they last longer--unless your engine is burning oil.

I have no opinion on the 4 prongers. Never used them.

 

I would say that's false, heat range is determined by the insulator used, not the electrode enhancement. What wears a plug out is the arc across the gap and the current through the resistor. I can get actual IMEP data tomorrow at work to verify this. (I work for Autolite)

 

whaa? i enjoy the nice lil 10-15 min job of checking the plugs... specialy when if im sprayin'...

 

i've heard a lot of good things about bosch premium plugs. From what i heard they cost much less than delcos but they're much higher quality. Never bothered to check for myself, go to the parts counter and ask for one of each and see for yourself.

Personally, i wouldnt buy any bosch product at all just because i dont like the way they misleadingly advertise their +2 and +4 plugs.

Yeah sure...there's going to be 4 sparks. I guess basic electrical law ceases to exist in your little plugs.

 

i preffer the ac delcos, i had platinum's in my 87 t type and they sucked, to much hype, i would stick to good ol' delcos, i just put some new ones on my 350 firebird, and i cant ask for more out of a spark plug, well the guy i bought the car from, hadnt changed them in years, they where burnt big time, i put the delcos and the car felt like new, way better gas milage, and response. go with delco's.-jorge

 

I just checked the heat range on an Autolite 3924 and APP3924 (standard copper and double platinum, respectively) and they are both rated at 275psi IMEP at 30° timing. Basically this means that at 30° timing, it takes 275psi of positive cylinder pressure to put the plug into preignition. The higher the IMEP, the colder the plug. A difference of 40-50psi results in the next heat range up or down.

 

Well, my car puffs smoke on hard accelleration (has 180k miles!) so... Bosch's are going! They are probably toast by now lol

I just can't get to my plugs very easy, so I liked the longer life idea.

AC Rapidfires huh? Any other recomendations? Or like you said, as long as I change them on a tune-up basis I'll be fine?

 

you should change them...

or you can do what most people have done since the 80s and wait a long long time.

the plugs in some cars have almost 80,000 miles on them... sure they would run much better if you change them, but they still "work".



its not like the non-platnium plug will make your car suddenly stop running or anything... lol

 

the easiest way to get to the plugs is by doing it underneath the car.

 

Ok guys, I work at pepboys and when I was changing my plugs I checked them all out. I didn't wunna go with platinums cause I have a carbed motor that runs rich and I change my plugs liek every 5k miles anyways. So I have 2 choices, AC Delcos for 1.19 or normal Bosch resistors for .99. I pulled both of them and the Bosch was alot shorter then the AC Delco and just looked like a higher quality plug so I got them and I have about a thousand miles on them and they haven't fouled and run great.

 

thats one thing i like about the bosch's. Nice and short and they stay away from the primaries.

which pep-boys do you work at? Lol... i remember they used to know me by name at the one over by Rt. 130 where the wawa is. When i had my POS mitsubishi eclipse all i ever prectically did was walk down to the pep-boys to get some part or another to get it running again.

 

Ah here's a piece of info from high school sciences (when you weren't asleep haha). I'd say the biggest reason why the platinums last longer than the coppers isn't because they are burning hotter (as stated above, the insulator is what determines the heat range) but because the platinum is naturally a harder metal with less conductive properties than copper. Once again that's why Iridium last longer than platinum, because it's a harder metal than platinum. More durable.

 

Good to know. Thanks!

I use a 50000 volt coil with my ignition and this thing still starts at -30C! That's something to keep in mind for those who live stateside, i.e., that is pretty darned good performance!

 

the regular copper bosch plugs, Bosch Supers or something like that, are shorter, which is great, but they have those damn screw on tips. those are not good for business

 

My old little V6 Camaro never did run right with platinums. Or more accurately...it ran AWESOME. For about 1 week. After that, I noticed it got progressively rougher and rougher, until it ran like crap just like it used to. When I changed the plugs out for AC Rapidfires, the car never ran as good as it did INITIALLY with the platinums, but it did run much better than when I changed the platinums out. And it KEPT running that way.

Not to mention, the electrodes on platinum plugs are TINY! I imagine it's very easy to kill those....

 

That's pretty damn quick, I can only change them in half an hour

I have ran the platinums for a while in various cars, and never had a problem (except in my SC'd 92 camaro). Cars running any kind of boost don't like platinum because they burn hotter and cause detonation (what ATI told me)

Matt

 

i was exadurating a bit there....


its more like a half hour to forty five min job.... but still, once you know how to do it, its not a hard or long job.

 

I have been running the Bosch 4s for about 2 years. I dont drive the car all that much (infact it's in another state right now) but when I do drive it I drive it hard. The plugs wear just fine and I have had no problems with them; so I guess I'll say yay for my B4s.