Most of your Stop Leak products are just designed to be temporarily used till you can fix the actual cause. It's like a bandaid on a cut. You don't leave that bandaid on forever.
Besides who knows what ill side effects they have on the drive train/coolant system. Did you ever see that crap come out of the cans? I've never used it personally, but it comes out in thick mucous, light pellets, thick oily substances, etc..
If I was your radiator I wouldn't appreciate you putting that crap into me.
I have used engine restore before. On my 318, and it seems to have worked pretty good. There is Lucas oil additives from what I hear seem to be a good product too, but have never used them.
You also can get BG auto additives from a reputable garage, and those products are worth their weight in gold. But they are more like oil additives for your engine and transmission, and flushing additives for your coolant system.
Additives mess up the chemistry that is already there- Not good.
Oil manufacturers spend millions on research, they know how to make your oil without the additives.
Its just an additive company trying to make a buck -imho.
Stop leak products are temporary- they dont repair the leak, they clog it up. Plus who knows how this stuff interfears with the stuff that its being mixed to.
I use fuel injector cleaner on my truck every once in awhile to keep the old chevy running ok. I have seen any problems. But I have not used any of those snake oils that make unbelieveable claims for horespower and effiency.
I use fuel treatment in every one of my vehicles, and all equipment. I use Schaeffer products, and believe they increase fuel efficiency. I have seen it improve my miles per gallon, and also acts as an upper cylinder lubricant, as well as an injector cleaner. It is also a stabilizer for machines that sit for prolonged periods of time. For my diesels...You bet I use addatives, I don't want to risk gelling up either.
Some may think they are a waste, but I believe they work, and count them as paid for in the protection they offer, not to mention the added cetane ratings that boost fuel efficiency.
I use Synergyn Oil products. Check out their site at synergynracing.com I put oil temp. gauges on engine and hydraulic system. Dropped the hydraulic oil temp by 65 degrees compared to Mobil 1
Their synthetic oils already have the additives in them.
Have used Sea-Foam fuel additive to help clean out injectors and top end. Seem to help with some hesitation, but nothing beats doing the repair the right way if you need it done. The best you can hope is that the additives such as this prevent build up and necessary repairs.