Bosch Platinum+4 Plugs

[OWL]

HI
I have standard spark plugs and wires in my 99 zx2.
I am wondering if there is any real gas saving benifit in these expensive plugs.
The standard plugs work fine would it be worth changing?
thanks
owl

[SuzukiSteve]

My boss just ran into some problems with his Bosch Platinum +4 plugs in his 3cyl Geo. All 3 cracked around the center electrode after many tens of thousands of miles. The engine was still running with the cracks but not as well. It had a noticable lack of power and mpg loss. Who knows how many miles he had to drive on cracked plugs. So he probably burnt more gas after they cracked than he saved before (if any).


With four prongs and platinum center they will take a long time to wear out but that doesnt help if they crack anyways. I would stick with cheap plugs. Check out rockauto.com they have really good prices.

[Ryland]

Most modern combustion chambers are shaped to work well with standard plugs, the +4 plugs seem to work best in large American engines.
I can't remember the details but the SAE wrote and published a paper on spark plugs a while back and explained how those plugs work in comparison to standard style plugs.

[some_other_dave]

Bosch has several types of platinum plugs. I have very strong opinions about them.

One is the very expensive and very unusual type that uses a lot of platinum and is the OEM plug for some very expensive cars. Those are good, but pricey.

One is the relatively-cheap platinum that you can get everywhere. It has a tiny speck of platinum in the center electrode, is not that expensive, and has spotty quality. I know several people who have experienced running problems with new or almost-new plugs of this type, including me. I also know several people who have had this plug fail in a couple of different ways, usually with the center electrode going AWOL. One had the ceramic insulator break, and part of it get caught in the wrong place, breaking his engine block. (No, he was not happy.)

STAY AWAY FROM THOSE PLUGS! I hate, hate, hate, hate, hate them!

As far as I can tell, the +2 and +4 plugs are the same crappy plugs with one or three extra electrodes tacked on. I would think they are subject to the same quality problems as the other type.

So I wouldn't use them.

-soD

[t vago]

I've never had any problems with these plugs. I run them in my Sebring and my Dakota, and have run them in many other vehicles in the past.

They may be more sensitive to detonation than the average plug, but that should be cause for investigating why the plug itself cracked, not an indictment of the plug itself.

[some_other_dave]

I never claimed to be wholly rational about these plugs.

-soD

[moorecomp]

I put the Bosch Platinum +4's in my 99 ZX2 almost 60,000 miles ago. I have had no problems with them and my lifetime mpg is just over 40. I can't say that the cost is worth it though and will be using the Motorcraft AZFS-32FE ones as recommended over at teamzx2.com. Gap is .048"-.052". Stay with the stock wires or the ones from Ford Racing. Also stay with the stock ignition coil. All this is based on recommendations from teamzx2.com. Lot of good info over there, not just performance stuff. Welcome, it is good to see another ZX2 here.

[cfguy2000]

I have had Bosch Iridium +4's in my 97 Corolla for about a year. I don't think it made much of a difference for power or economy. Supposedly the Iridium plugs can last over 100,000 miles.

[buglao]

Try NGK or ND plug they are very good.