Bosch Platinum +4 Spark Plugs Good or Bad?

 I hear mechanics complaining about Bosch Platinum +4 spark plugs. They say there really not for V8 motors and really only work in 4 bangers. I just wanted to get a few people's opinion on them good or bad.
 
 
                                                                                            Will


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bad! there has been a lot more people that had problems with those plugs than to those that had none. just replace with what it came from the factory and avoid the problems. btw, sweet shot! 

I have 4 years and 65,000 miles on my Disco running Bosch Platium Plus 4's and Magnacor wires.
People who usually bad mouth them are pass on second or 3rd. hand info and have no first hand experience using them.
As part of doing my head gaskets I am going to up grade to their new Fusion plugs which is even a step up over the Plus 4's.
Because of my referals, I have about 70 plu people using them and not one has had a bad experience, most really liked the increase in low end torque.
By the way, up untill last year I also had a 420 SEL with nearly 200,000 miles on it, close to the last 100,000 miles were run on Plus 4's.
Go for it and if you don't like them, Bosch will give you a full refund, I don't know another plug manufacture that will do that.
Mike

So what have you decided to do for plugs?
Mike

I am goin with the Bosch 4 plugs. I'll let everyone know how it goes. I have a G-Tech pro and as of right now i'm running anywhere between 15.90ET and 16.20ET in a 1/4 mile with around 180-205 horsepower and around 190-220 lb ft of Torque. Did you ever change to your new Bosch plugs???


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I have recently changed to Bosch +4s w/ Magnacor 8mm wires as well. So far only 20 miles on the set up but no problems!

Now that I got my bosch plugs in I had to replace my o2 Sensors. But it still doesn't feel like I'm getting all my power out of my Rover. When I stomp it to pass or get up to any speed it doesn't wanna go over 3500rpm's unless I use sport mode. It wasn't like that before I had bad wires. But I didn't notice a difference in regular mode and sport mode until I got my new plugs and wires. Any ideas on what it could be Mike???


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Did you replace your wires at the same time?
How many miles on your engine?
Mike

Yes everything was replaced at the same time. Plugs wires all the gaskets. I just had a P0455 Evaporative Emission System Leak Detected (Gross Leak/No Flow) code pop up today. Could that be it???


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check your gas cap and make sure its tight.

This is a major evap leak that is knocking your power down not a leaking gas cap.
Have you resolved the problem and got the old engine up and pulling know?
Mike

well i have plenty of experience with Bosch...first off bosch isnt original equipment in any vehicle on the planet...you should put back into your vehicle what it was designed to run on...champions i belive just make sure they are double plats. Bosch has caused me nothing but problems in my 10 years of turning a wrench, and you`re right you are not going to notice anything positive with those, i suggest champion double plats or NGK double Plats...and Borg-Warner Custom Fit Wires...give it a try in any car...Fords= autolite plugs Honda= NGK chrysler= champion and so on and so on...think about it, your car was designed to run at its peak performance with Champion plugs...why not put those back in it?

Well, you are wrong, Bosch is a standard plug for many European vehicles like Mercedes, BMW and others.
Also, just to set the record straight, our Rover engines, when first designed came with AC Delco plugs, then Rover switched them to Champions.
If you are wanting to talk about failures, then we should talk about the poor quality of the B/W p;ug wires which don't hold up to our engines heat.

WOOOO!
 
I've got Bosch +4 in my RR 4.0se for some time now (last summer) runs sweet (ran good w/ old champs tho')
 
I've had some $5 ea autolites in my 4.0 disco for maybe a year & it runs great too!
 
I'm not brand loyal, but I second Mike on VERY GOOD plug wires - these babies can make heat!!
(Not enough room for my resume since 1959) - put cheap parts on cheap cars

quote:

ORIGINAL: LandRoverSE

Now that I got my bosch plugs in I had to replace my o2 Sensors. But it still doesn't feel like I'm getting all my power out of my Rover. When I stomp it to pass or get up to any speed it doesn't wanna go over 3500rpm's unless I use sport mode. It wasn't like that before I had bad wires. But I didn't notice a difference in regular mode and sport mode until I got my new plugs and wires. Any ideas on what it could be Mike???


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Are you still fighting your power issues and getting over 3500 RPM's, if so give me a shout sometime and lets talk about it.

imho, I am a little skeptical when it comes to plugs and performance anyhow.  First off, I don't put 100% faith in something because it was OEM.  I've seen many situations where the original manufacturer went with a cheap-crappy design because it saved them money in the long run.  Going off of this same though, who is to say that the spark plugs are any different?

Next, the internal combustion engine is basically controlled explosions.  The bigger the bang, the more power.  If I pour 1 OZ of gasoline on the ground and light it with a match...and then I pour 1 OZ of gasoline on the ground and light it with a lighter and do the same using an Oxy/Acetylene torch...which one is going to generate a bigger "BOOM"?
 
I'd say they are all going to be about the same.  Gas is gas, it's going to ignite.  The only issue is if your plugs are fouling and they don't produce enough of a spark to ignite the fuel/oxygen mixture...but I don't see how having two hundred gazillion volts going to a super Bosch + 9000 plug is going to produce any extra horsepower.  You're going to reach a point where the mixture is ignited and that's that. 

From there it becomes a matter of increasing oxygen and fuel, increasing compression, increasing stroke and bore.
 
 

The plugs and wires haven't caused this code.

My bosch fusions are great. They really made my disco more peppy (most likely due to "new" plugs/wires). Either way, they have not caused any problems.. so I''m happy.