I had an old !981 Datsun 310GX that I bought with 150,000 miles on it
years ago.  It always had a little trouble starting and mileage was
rather poor with significant oil blow-by.  At 165,000 miles I tried the
engine restore that I believe uses a nano particulate aluminum filler.
Suprisingly the restore worked wonders in this rig.  No more oil
consumption, excellent starting, and nearly factory spec mileage.  I
put in a can of restore at every oil change and the car ran great.
When I decided to get rid of the car at 200,000 miles I did one last
oil change and figured since Im ditching the car, heck with the
restore.  Car went back to burning oil, poor starting, and significant
reduced mileage.  I am a rather strong proponent against these modern
snake oil products, but with a worn, loose engine the restore did an
excellent job, although I did have to use it every oil change.