oil additives and mystery

[Mike C]

In your cape dory , a single cylinder diesel like the ones in the CD25 and CD27.

Has anyone used the oil additive called Mystery Oil, a local mechanic says I should add this to every tank plus. I should add to the fuel, add to engine oil Plus because marine fuels stand for a long time I should also add algae control and a fuel conditioner.

When you buy diesel for your boat is it not the same fuel as car or truck diesel. But are these additives already in the fuel when you buy it. And how long can you store diesel fuel before it becomes a problem for your engine and pre-filter

[Kato]

I'm no expert but I'll try to answer:

oil additive called Mystery Oil, a local mechanic says I should add this to every tank

Who knows. Many swear by the stuff and others say it doesn't make a difference. Bottom line is probably can't hurt if you can afford it. Acts primarily as an extra lubricant.

marine fuels stand for a long time I should also add algae control and a fuel conditioner

Sure.

When you buy diesel for your boat is it not the same fuel as car or truck diesel. But are these additives already in the fuel when you buy it

Yes and no.

And how long can you store diesel fuel before it becomes a problem for your engine and pre-filter

Depends. How cold is it? How moist it? How clean were your tanks? How clean was the fuel? Have you been living a good life? Bottom line keep fuel turnover a quick as possible.

Lot of questions there...

[Ed Haley]

I use Marvel Mystery Oil in my fuel and oil in my RV. As a fuel additive, it acts as an upper cylinder lubricant and cleaner. It also may free up a lot of crud in the fuel tank and lines. If you add it to your fuel, be prepared to change the fuel filters a lot sooner and more often for a while while it takes effect.

[rtbates]

Mike:

Yes, it's the same fuel. The color difference you might have noticed is differentiate between land (pay fuel tax) and sea(don't pay fuel tax). Seems the feds don't want land based vehicles using sea based non taxed diesel. Go figure.

Marvel mystery Oil is good stuff, BUT it's not a diesel additive as such. Like someone said it's an upper cyl lube and all around slippery stuff. What you need for diesel is a biocide/cetane booster.