[victorgte]

I’ve used additives for years. Some work and some don’t seem to work.
Slick 50. Saved my TR7 when the engine lost its oil filter at 40mph. Engine did not seize up. Ran fine until i sold it 18 months later. With fresh oil and filter of course!
Redex. I’ve got no positive proof of its abilities. Use it when it’s on offer.
Engine oil stop a leak. This does work. My weeping crank oil seal weeps no more on my L series diesel Streetwise.
K seal. Just avoid it at all costs.
There are no doubt more I’ve tried but can’t report on anything positive as I can’t remember. I’m sure I will think about more and post again.