What type of spark plugs are good?

[Explorer94GV]

u all know by now im getting new engine in my X has 110k on it and the other owner didnt do **** to this X but abuse the hell out of it. ive replaced trans 2k miles ago just added a k&n drop in filter getting new v6 4.0 liter engine and now want new plugs. i dont even need to look at them and can tell you that they are stock. what brands are good out there. give me place to purchase brand and price. thxs!

 

[jjue]

I just use the stock Motorcraft Platinum electrode plugs since my roommate uses either them or NGK plugs on all his vehicles, including his '67 Mustang which he drag races and was running 12.40s in the quarter on an EFI 302 with Ford J heads on motor until he started porting through a bunch of cylinder heads and then decided to build the 351W. I think that he will be able to run the new engine at the track in the middle of March, and he started all of this in October 2000.

 

[Jason_25]

Stock motorcraft plugs are best. Get the platinums if you want them to last a little longer.

 

[RON COX]

Stick with the Motorcraft plugs. I've tried others and the engine doesn't like them.

 

[Alec]

Yup, stick with Motorcraft ones. I just put a set of double platinums in mine. Though I did get some that are 1 heat range cooler cause of the s/c and n2o.

 

[Kontrol-Trak]

I use Bosch platinums with no problems

 

[RTStork]

I too, have used Bosch platinums and I like them. I haven't tried the Motocraft platinums yet. Does anybody know if the 99 5.0 Explorers came with the platinum or regular plugs?

 

[jjue]

Since you have the 302, they should be platinum. Actually, the ones that we have since we both have 302s is that one side of the engine has platinum on one electrode & platinum on the other side for the other side of the engine. It's called R&D. Regardless, we end up buying double platinum tip plugs as its too confusing to know which cylinders get what plugs.

 

[Stephen]

If I'm not mistaken the BOSCH platinums and the Motorcraft platinums are one in the same...

 

[rpr]

Another STRONG recommendation to stick with Motorcraft. I thought I was doing the right thing by buying one of the newer platinum multi-electrode plugs (I think they were Bosch). It felt like I lost 50hp, and yes...they were gapped correctly. I returned them to Pep Boys (I was honest with them and they wrote them up as defective). I then went with the Motorcraft, and all was good again.

 

[Explorer94GV]

well sounds like everyone agrees stick with motocraft thxs

 

[01EB5.0]

I run Bosch Plaitnum and am happy with them...

 

[410Fortune]

Over the years in my 2.9L and now my 4.0L I have tried many different plugs. From Autolite to Motocraft.
The NGK platinums work well
The Motocraft platinums work well too.
I prefer the Bosch Platinum +4's.

These engines seem to like them when modified.
The engine's responsivness is improved.
Gas mileage is slightly better as well, every penny counts...

The Bosch +4's dont seem to last as long as the other platinums but they have also come down in price.

I think they were $3.50-4 last time I got a set of 6.

Dont overlook the qaulity of the wires either and be sure to use a dab of dielectric grease (tune up grease) on the plugs, it really helps keep the moisture out of the boots (if you have JBA headers on a 4.0L the flage that bolts to the head will actually create a dam of "well" right around the base of the spark plug. If you wash your engine or go forging through deep water, you will want to try and blow or soak up the water that builds up in there, it can cause a bad miss. May be true with other headers as well...)

 

[rpr]

Seems like the majority of the folks who have had no problems with the Bosch Platinums do not have the SOHC engine. With my '97 SOHC, I experienced a significant decline in engine performance when I tried the Bosch Platinums. Maybe just the SOHC doesn't like them?

 

[410Fortune]

Thats possible.

OKay so dont apply what I dais to the SOHC

It seems that people either love the +4's or hate them.

I love them
There are some factors that may play a role in this as well.

I live a mile high in Denver.
I have extensive intake and exhaust mods
I run only 91+ in my baby


A few of my friends here also love the Bosch +4's.

Of course without A/C and a bunch of other later model Explorer junk around my 4.0L I dont have a hard time changing plugs. If you do you might want to stick with Motocrafts or NGK's so you dont have to change them as often.

I know the SOHC engine is not picnic to replace spark plugs on either, but at least they got the thermostat into a reachable area!!!!!

 

[01EB5.0]

The +4's are supposed to last twice as long as standard plaitnum plugs. i have had mine in there for 40,000+ miles and I still get excellent performance.
Also for those of you that would like to spend less on a set of Bosch plugs, Bosch recently came out with a +2 plug. It has 2 electrodes instead of 4. it is different from the splitfire because the +2 has the electrodes opposite each other.

 

[410Fortune]

I out those +2's in my fiance's old CRX si.
What a difference!!!!

Now I might try them in her 97 YJ