tune-up question
 

Any thoughts on spark replacements other than OEM?

Re: tune-up question
 

Two thoughts:
1) You shouldn't need to replace your plugs for quite awhile. I wouldn't bother until you have at least 100,000 on the clock.

2) I like the Bosch +4. The price premium isn't that bad in an absolute sense ($12) and I haven't had one that wasn't gapped properly out of the box or that failed prematurely.

Re: tune-up question
 

I'd trust the OEM Motorcraft. Spark plugs are all so application specific these days, I feel like the Ford engine engineers know best. Other aftermarket brands tend to simplify their offerings which might compromise a desired operational element - especially for our unique engines. A minor compromise in heat range, electrode design, etc. might be enough to affect the optimum operation of the engine.

Re: tune-up question
 

I totally agree with Red that your not going to improve anything and may hurt MPG with a aftermarket spark plug. My recommendation is to always use the OEM part number for every make and model vehicle that the manufacturer recommends. Everything is fine tuned from the PCM, coils, wires and spark plugs to give you the most efficient ignition as a package. You start modifying separate parts you could affect other parts performance even in the exhaust system.

Once I took a high performance aftermarket distribitor to a race mechanic to fine tune it for my GT 500. He checked out my stock dual point distribitor and said take back the aftermarket distribitor and get my money. He showed me my stock distribitor handled the highest RPM my engine would be good for (7,000) on his machine just fine.

I've had problems using other brands on stock engines more times than not so I stick with something I know works now.

GaryG

Re: tune-up question
 

I was having rough idle on a cold engine at about 75,000 miles.

I changed my plugs to the Bosch +4 just a few weeks ago because it was quick and easy to do. Plus, they were what the local parts shop had in stock, and I didn't want to wait to special order the OEM type. I'm pretty sure they were $5.99 each IIRC. If I'm wrong, I'm close. I would not have paid $12 each.

The rough idle instantly went away.

The original plugs did not look that bad to me. They were tan, not black or grey at all. Looked quite normal. The "threads" of the plug were "rusty" though.... due to the fact if you wash your engine, water collects around the base of the plugs... it cannot get to the engine, but the "rubber boots" are more of dust covers, and apparently, not water tight.
I took photos of the orginal plugs and I will post them on here soon for some opinions.

I tell you one thing, the Bosch sure "look" more impressive than the original.

As far as MPG goes, there's probably not a 1% difference between expensive and cheap ones. Cheap ones just have a shorter lifespan and you should change them more often.

HTH,
-John

Re: tune-up question
 

Over the years & miles I've played around with different plugs.

On my Mustang (251k) the Bosch +4s did not give as good mileage as the Motorcraft plugs. Can't really say why but across the 55k I had them in the recorded mileage was about 0.3 to 0.4 mpg less than the Motorcraft plugs.

In my Suburban (377k) the Bosch +4s did better by maybe 0.2 to 0.3 mpg.

Curiously, Champion plugs, which I used to put into my Duster (a slant 6 that went about 160k & had the old point ignition system) every 10k, performed the worst. Maybe 0.5 mpg less than other plugs.

I never could establish a pattern or reason for the above. Just the empirical data.

Re: tune-up question
 

I wonder if you washed carbon up under the spark plug boot and had some tracking going on. This was a common trick to cause missing for those tune up competitions. They'd put a light pencil line all the way along the insulator, put the boot back on and the thing would miss like crazy.

Re: tune-up question
 

Plugs are wierd little creatures.

The only plug that runs right in old air cooled VW's is Bosch. The best plug I found for Datsun (then Nissan), Toyota or Subaru was NGK. My F150's all liked Autolites... Always had to replace Champions before the next scheduled tune up in any car.

If you can get 75K to 100K outta a set of Autolites in the FEH, I'd say that's pretty good. Might be inclined to stick with them.

Re: tune-up question
 

As an experiment I put in a set of +4s in my Escape, did not get any more mpgs but didnt run poor or different. 70k to 90k is a reasonable service interval for these engines.

Re: tune-up question
 

I changed the plugs in my 2006 FEH not too long ago. I was not even remotely close on the mileage, but I remembered that when I changed the plugs on my 2002 Escape Ford had not bothered to use any anti-seize on the original plugs. Ford is, at least, consistent....no anti-seize on the FEH plugs, either. They weren't in bad shape, but I would not want to leave the original plugs in for 100K miles. I was pleasantly surprised to see that Ford actually used NGK Iridium Long Life plugs in my FEH. These are the best plugs NGK sells (approx. $12 each), better than the more common NGK Iridium IX (approx $8 each). THE OE plugs Ford used in my FEH are FAR better plugs than anything Bosch sells, especially the +4's (approx. $6 each, marketed for the Splitfire crowd). It''s something you do infrequently, why not do it correctly?