Mr Moedip: You said you've been using one of those miracle additive for 10 years and you still can ''feel'' a quieter operation, smoother idle, better mileage, reduced heat.....You have quite a memory.
DuraLube and a number of other miracle additive producers have been sued by the Federal Trade Commission for deceptive advertizing and false statements. Read this:
Duralube lost in appeal.
Sorry to dampen you illusions but you have been had by a very well designed marketing campain. A large number of companies have been in business for much more than 16 years selling lousy products.