I clearly do not have as much experience as you guys but I'll put my two cents in anyways to contribute to this discussion:
I've always been tempted to try additives in hopes of keeping the engine 'healthy' for the long haul but fortunately I never have, afterall; everything seems to be working just fine so far (at 190,000 miles) so why change the situation if it's not broke yet.
...and high-mileage oil... - I took my 1st gen into the dealership about 5 months ago for a heavy "tune-up" (really, all they did was mostly a 90,000 mile service I think). Anyways, I looked closer at the paperwork last night (now that the car's in my name I'm more comfortable taking care of repairs/maintenance myself) and I noticed they put 5w-20 in it. After some research I found out that Ford switched to using this for better gas mileage??? Is that true? Manual and engine bay says 5w-30, and on another note: they put in DOT4 instead of DOT3 which the manual and housing cap calls out for and I'm not sure why they did that too??
Gonna cut to the chase
I appreciate all this information, and what I've learned from this thread and the "which oil/filter do you use?":
-Not gonna take it into Jiffy Lube ever again after I noticed that cheap ass oil filter down under there last weekend
-Going to stick with OEM oil/air filters (until I find something better)
-Going to stick with one brand of oil (this was mentioned in the other post, and it's a great idea, my expy's had all different brands in there)
-I got my free sample kit coming in the mail from Blackstone, so I'll do a test after I put fresh oil in there, and see where that takes me
Lastly, I'm still up in the air between using conventional/high-mileage/semi-synthetic and synthetic oil. My car's always had conventional....isn't high-mileage still conventional or is it semi-synthetic? I don't know, I feel iffy about making a change into synthetic because everything seems to be fine at 190,000 - would love to see her go for half-a-million....what do you guys think?