1997 Aerostar

You are, of course, using Autolite platinums? They should last 100,000 mi. & then some.

Rob

On the 4.0 you NEED the double plats - or half of the plugs go south while the other half is still good. If you are too CHEAP to use the specified plug, change them every year. On my 3.0 I used standard non-plats and changed them every 50,000km. I figured it was better that way than letting the plats sieze in, then pull the motor to replace the plugs.

Thanks for your input you two. I've always been of this mind but was scared that the engine would do the exact same thing to the much higher priced double platinums. You can understand a concern like that, I'm sure. L89