running gasoline/diesel mix in an emergency

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ofer

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Joined
Apr 10, 2020
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530
Location
USA
Vessel Name
Unicorn
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1970 50' DEFEVER OFFSHORE CRUISER Timber
What are the options if any on adding gas to diesel to make a few more miles.

any percentage mix that are acceptable and or addling ATF or something like that to the mix.
 
A small percentage of ATF will not impact most diesels. Not true for gasoline, though.
I wouldn't risk it. Modern diesel fuel has less Sulphur than when older engines
were designed so they are already getting less lubrication than before.

Modern gasoline also contains alcohol-like compounds that attract water so not great
for fuel that will be stored in a boat's fuel tanks for years in some cases.
 
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DO NOT, repeat NOT add gasoline to diesel. The risk of explosion and severe damage and/or death is too great. The difficulty in uniform mixing and the vaporization of low chain hydrocarbons in gasoline make it very dangerous on vessels which are not built with gasoline specified equipment.

Spend your time doing something else, anything else.
 
What a strange question and what constitutes an emergency? If I was running a pair of older Detroit Diesels and my life was in jeopardy I would be pouring everything into the tank.

If I was going to be a mile short of the fuel dock and my emergency was being embarrassed that I ran out of fuel, don’t think I would chance pouring anything into the tank.
 
And why would you carry a can full of gas instead of a can full of diesel?
And why would you plan on cutting it so close that you would need a few more miles?
Sounds like Pi$$ poor planning.
 
I am NOT suggesting that you do that. However, I knew a fellow who inadvertently put gas into one of his tanks. THis was a P/U truck, pulling a 5th wheel trailer, with an auxiliary tank in the bed.

NO place to get rid of it so the advice was run on the contaminated tank on low load, flat areas where the engine was not working very hard.

He had a switch on the dash to control which tank fed the engine. WHen he could see a hill coming he would flip, EARLY, to the straight diesel tank, and climb the hill. When off the hill he flipped back.
It worked and as he burned it down he added diesel untill the tank was all diesel.
He also kept his speed down. Less speed uses less power.


I am not suggesting though that in a boat it is a good idea. His P/U tanks were totally open to ventilation so no fumes collecting. He had the ability to use the contaminated tank under low load conditions and under high load conditions flip to the straight diesel.

You won't have that. You could fill the bilge unknowingly with fumes. You won't be able to flip tanks, at least not easily or readily, depending upon load.

As you use your diesel and then add gasoline you will be adding to an already low tank which means the % of gas to diesel will be very high.
Not good.

If there is any question about range then you should find and use some means of carrying extra fuel. Jerry jugs, drums, bladders, extra tankage somehow. The extra storage has been done many times.
 
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DON'T DO IT!!! Is the Admiral asking you about your life insurance.
 
I would never do it. Just monitor your fuel usage and plan ahead. I have been boating for 55 years and the only time I have run out of fuel was when I was 16 and our family was out for the day. I told my dad that we needed to refuel before we started across Lake St Clair but he “knew” better and didn’t refuel. Halfway across the lake we ran out of gas. Immediately two of the people started throwing up since we were rolling a bit. I never ignored my planning again.
 
Gasoline definitely does not like 16-17 to 1 compression ratio,, and becomes VERY volatile including total destruction of a diesel engine..>>>Dan
 
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What a strange question and what constitutes an emergency? If I was running a pair of older Detroit Diesels and my life was in jeopardy I would be pouring everything into the tank.

If I was going to be a mile short of the fuel dock and my emergency was being embarrassed that I ran out of fuel, don’t think I would chance pouring anything into the tank.

I agree, a strange question. Call for a tow if you run out of fuel.
 
That’s why you have towing insurance, right? We all make mistakes. Don’t turn it into a disaster.
 
ok.

I have been boating for 40 years and NEVER run out of fuel or needed a tow.

here it is....

I am traveling far away from any assistance services.

I am 400 miles from my intended destination in rough conditions and I think i have 200 gallons of diesel left. I do a fuel check and realize I sprang a leak and only have 100 gal left in a 200 gal tank. I have an aux tank with 100 gal of gasoline.
If I dump it into my diesel tank what would happen?

Tank will immediately blow up and boat catch on fire due to a chemical reaction?

my non computerized Cat engine seas to function as soon as the new mix is interduced into the cylinders?

Engine may over hit at high RPMs
 
I would not mind to mix vegetable oil but would never had the idea of mixing gasoline in a diesel engine.

L
 
Why are you carrying 100 gal of gas on a diesel-powered boat?
 
I don't get this thread either. Hard to imagine any likely scenario where this issue would ever come up. How much diesel could I mix with gas before my 454's sputter to a halt? I don't know, it'll never happen.
 
Back
Once into big boats with a strap on or towed sport fishing boat large gasoline storage is quite common. For large yacht charters the water toys burn a lot of gas with several hundred gallons of gas storage not uncommon.
 
Any chance you can put in at an intermediate port and refuel, at least partially?

Arrange for a few drums of fuel to be brought to you.
 
ok.

I have been boating for 40 years and NEVER run out of fuel or needed a tow.

here it is....

I am traveling far away from any assistance services.

I am 400 miles from my intended destination in rough conditions and I think i have 200 gallons of diesel left. I do a fuel check and realize I sprang a leak and only have 100 gal left in a 200 gal tank. I have an aux tank with 100 gal of gasoline.
If I dump it into my diesel tank what would happen?

Tank will immediately blow up and boat catch on fire due to a chemical reaction?

my non computerized Cat engine seas to function as soon as the new mix is interduced into the cylinders?

Engine may over hit at high RPMs

Can we assume you are stating a hypothetical situation here?

I once had a client (sued for a related reason), who told me about a fuel delivery to his gas station where a gas/diesel mix occurred by the delivery operator mistakenly putting his hose into the wrong tank. His statement at the time was that something like 10% of one in the other was the tolerable limit.

That would never be part of my backup plan.
 
I don't get this thread either. Hard to imagine any likely scenario where this issue would ever come up. How much diesel could I mix with gas before my 454's sputter to a halt? I don't know, it'll never happen.

Not the same
 
Back
Once into big boats with a strap on or towed sport fishing boat large gasoline storage is quite common. For large yacht charters the water toys burn a lot of gas with several hundred gallons of gas storage not uncommon.

thank you!
 
Can we assume you are stating a hypothetical situation here?

I once had a client (sued for a related reason), who told me about a fuel delivery to his gas station where a gas/diesel mix occurred by the delivery operator mistakenly putting his hose into the wrong tank. His statement at the time was that something like 10% of one in the other was the tolerable limit.

That would never be part of my backup plan.

Yes, hypothetical although a version of it is not probable but possible.
 
Possible consequences range from scored cylinder walls or bearings due to low lubrication to a blown head gasket or bent connecting rods, requiring a complete rebuild. No matter what, you will significantly reduce the service life on the engine. Ask yourself if doing this to avoid inconvenience is worth rebuilding or replacing your engine(s).
 
If you're looking for better mileage, use a good fuel conditioner that includes a cetane booster. Mine gives a 10% mileage boost for about 10¢ a gallon.
 
If you're looking for better mileage, use a good fuel conditioner that includes a cetane booster. Mine gives a 10% mileage boost for about 10¢ a gallon.

What are you using?
 
ok.



I have been boating for 40 years and NEVER run out of fuel or needed a tow.



here it is....



I am traveling far away from any assistance services.



I am 400 miles from my intended destination in rough conditions and I think i have 200 gallons of diesel left. I do a fuel check and realize I sprang a leak and only have 100 gal left in a 200 gal tank. I have an aux tank with 100 gal of gasoline.

If I dump it into my diesel tank what would happen?



Tank will immediately blow up and boat catch on fire due to a chemical reaction?



my non computerized Cat engine seas to function as soon as the new mix is interduced into the cylinders?



Engine may over hit at high RPMs
You are suggesting a 50 - 50 mix. I would expect the engine to be destroyed long before you make 400 miles.

I know of one engine designed to tolerate a gas diesel mix. The ratio is 10% gas. It is to be used for cold weather starting only, immediately switching to 100% diesel upon starting to run.
 
ofer,


Octane is the explosive value of fuel. Typically Gasoline has 87 (or More) Diesel fuel has about 10 Octane. So Gasoline has about 8.7 times the amount of explosive power of Diesel. Don't do it, it isn't just bad for your engines, they can literally explode like having a grenade go off in each one of your cylinders (with the accompanying shrapnel).



Star
 
I'm one that just cannot see this scenario played out at all. Only if a really poor helmsman were running the boat, and/or really exceptional bad luck. But why would a diesel boat be carrying many gallons of gas?
 
Not sure what the angle of adding gas to diesel but have heard the old time loggers up here in northern Maine talk of adding a little gas to diesel tanks on equipment that had gel the fuel due to cold (-30-40) to keep them operating, I have no idea what ratio they used. I will add 10% kerosene to the fuel in my tractors (old) during a cold winter to decrease the gel temperature, but also add Lucus top end lubricant. I was taught that by a old time farmer who was a great wealth of knowledge, he always said the only use for gasoline around a diesel was for cleaning parts in a pinch. :)
 
I'll try not to be toooo crass... but... Don't Be Nuts!

As was mentioned before in posts... carry extra tankage with diesel fuel - NOT Gasoline!! Don't risk your and other's life.
 
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