My wife, kids and I all drive Fords that have 130,000 to 230,000 miles on them. My last T-bird went well over 200,000. My last 2 Taurus company cars went 150,000. All have had zero engine problems. All were maintained with dinosaur
oil and regular changes. I can't help but believe that money spent on additives would have just been dumped in the recycling barrel.