I was looking at the ignition upgrades for the 4.6 on Troyer's site and was reading some of the details and noticed that it said you need to change the stock ignition every 3 years or 36000 miles. Now I was told that platinum plugs are good for 100,000 miles. The rest of the system I don't know how long they should go without being replaced. I know on pre-97 trucks you had to change every 36000 miles. So what is the deal? If I upgraded the system how long will it last?

 

Don't be shy.

 

It's what they tell you to keep the maintinence costs down, the plugs will last you 100K and then some, but they will be tired.

 

I don't believe that any spark plug will maintain peak effiency at 100,000 miles. On my personal vehicles, I tune 'em up every 50-60K miles. A free afternoon, a little time and a fi****l of spark plugs is cheap.

 

Platinum tipped 100K miles spark plugs are nothing other than a marketing ploy by manufacturers to keep long term maintenence cost estimates down. Those plugs look like cooked pig fat at 100K miles sometimes, and cause you to loose performance and MPG.

Change no less than every 60K for optimal conditions.

 

Platinum plugs are somewhat of a joke, as the electrodes are not made of platinum, but platinum coated. Double platinum = two coats, so on and so forth. Some manufacturers dont even reccomend gapping these plugs as you could wear of the platinum. None the less I would never install plugs without gapping first as they take a beating during shipment, and whose to say the "pros at Autozone" didnt drop the box on the floor on accident during stocking. I use a wire type gapper to gap the plugs and use the slotted end to open or close the gap accordingly at the base of the electrode so firing area is not affected like it would be with the 99 cent parts counter special gappers. As far as whether to go with platinum or not, the best thing to do is always go with OEM Motorcraft plug, if it calls for platinum use it, if not dont.