Installed A New Set Of Bosch Plugs and WOW

[The Critic]

Originally Posted By: mechtech2
Plugs don't color like they show in old manuals.
Not even close.
Fuel is one big reason why.


When you seafoam or do any activities that may potentially foul the plugs.

With the new spark plugs in, so far, it seems like the fuel economy has improved by about 10%. Of course, I have not filled up yet so I cannot tell for sure.

 

[Scdevon]

There was nothing wrong with those old plugs.

A 10% fuel economy increase? I doubt it.
Often, a set of new plugs will make a car run worse.
Big, fat, worn gaps on old plugs give a terrific hot spark and great performance.

Those old plugs in the photos weren't even broken in yet.

 

[PandaBear]

You don't know for sure until you fill up a couple times. If you feel a difference with a 20k plugs, something was wrong, and may not be visible (minor carbon trace, internal damage (resister), etc. My experience is that copper plugs don't feel sluggish until at least 25k, if you can feel it, something was wrong with the old plugs. I'd say keep the old ones around but don't plan on reusing them. 10% on a 40mpg car is 4mpg, that's a lot.

 

[PandaBear]

BTW, how come #1 is missing the gasket?

 

[crazyoildude]

They are fine

 

[SteveSRT8]

Nothing works for everything.

I, too, have installed plus 4's in a dozen different cars and trucks with nary a miss or sputter. Took one set all the way out to 200k miles!

And I am always amused by the plugs sticking in the heads or stripping out.

That cannot be blamed on the plug. Just the person installing/removing them.

 

[JHZR2]

Originally Posted By: AcuraTech
Bosch plugs suck in anything other than German cars. I've seen Honda engines fail emissions with Bosch plugs, and then pass after changing to NGK.


and all euro cars we've owned take NGK!

 

[FL_Rob]

Originally Posted By: tom slick
backup for what occasion?

For doing a boneheaded thing like cracking an insulator (yes, Iv'e done that)or to use for a parts store run,a few spares at least are a good idea .

 

[Vizzy]

Originally Posted By: SteveSRT8
Nothing works for everything.

I, too, have installed plus 4's in a dozen different cars and trucks with nary a miss or sputter. Took one set all the way out to 200k miles!



And I am always amused by the plugs sticking in the heads or stripping out.

That cannot be blamed on the plug. Just the person installing/removing them.


I know that quite a few mfrs specifically state NOT to use antiseize when installing plugs..VW is one of them....so instead I simply put a little 10/30 oil on threads...I haven't yet had a problem removing plugs even after 60k miles...does anyone know why this would be a "bad" idea?

 

[The Critic]

Just filled up today. About a 15% improvement compared to the last tank with the old NGK plugs.