Diesel V's Petrol

[bearmcnally]

Hi Hatters
"Quote "
Petrol is more efficient fuel but it effects a lot in causing pollution. On the other side, diesel is more environmental friendly, cheap and when compared to petrol causes less pollution effects." Unquote"

Cheers Bear

[Dolphin]

Diesel is actually slightly more enery efficient (or dense) than petrol.
Diesel has 46Mj/kg. (Mega Joules per kilo gram)
Petrol has 44.8 to 46.9 Mj/kg

When you take the specfic gravity of the two fuels, Diesel 0.820 to 0.950 and petrol 0.737 then you get
1 Litre of Diesel has 37.2 to 43.7 Mj (MegaJoules)
1 Litre of Petrol has 33.0 to 34.6 Mj

The bonus for me is that diesel is a safer fuel to handle, doesn't give off volatile vapours that are heavier than air and can collect in the bilge. There is no spark and high voltage ignition sources.

Petrol exhaust contains more carbon monoxide than Diesel. Diesel exhaust condenses to a greasy dust.

So the answer is simple, GO DIESEL!

Greg.

References
http://www.kayelaby.npl.co.uk/chemistry ... _11_4.html
http://www.simetric.co.uk/si_liquids.htm

[Phillip]

Well I can run my Diesel on less than 1litre per hour,

but to do the same in petrol would be about 6 litres PLUS


So where are you going to store all that petrol?

Petrol will go BANG! Diesel won't!!!!!


Hell, I even get worried about the 5 litres I carry for the dinghy outboard!

Diesel is quieter than petrol, remember Shaun [with Night Cap] said he was glad to take the earmuffs I recommended on his trip to Sydney last year [or the year before].

Going north you need to cover a max of 200nm between fuel on one part of the QLD coast. I did that with 60 litres and had plenty in reserve when I completed that section. If I had petrol that would mean about 200 ltres!!!

Where do you put that on a Top hat?

Oh, and petrol smells worse than diesel!

Phillip.

[Tales]

I do suspect John's motive in starting this thread but here goes anyway!

I too can run 1l/hr with my petrol 6hp Suzuki and being a 4stroke (and the exhaust pilot hole plugged) it is pretty quiet as well.

If I had a dinghy motor it would use the same fuel.

No growth on the prop either!

I can go backwards with ease steering with the motor tiller.

Current motor is 6 years old and gives every indiaton of lasting another 6 with ease. Replacement cost about $2000.

If I had pots of money however I would have a diesel tomorrow!

Cheers,

Tom

[Miker]

I'm with you Tom,

I have an 8hp 4 stroke, using about 1.5 litres per hour. Stored in the port cockpit locker with a breather. Works a treat, although cavitation can be an issue in some seas.

Again, if I had buckets of cash, I'd change to a wee diesel as well.

Michael

[David]

The bonus for me is that diesel is a safer fuel to handle, doesn't give off volatile vapours that are heavier than air and can collect in the bilge. There is no spark and high voltage ignition sources.

Petrol will go BANG! Diesel won't!!!!!

Never be complaicent about this Diesel DOES give of vapour and hydrocarbon vapours are heavier than air.
Diesel is classed as a combustible fuel not a flammable(petrol/lpg), but all fuels have a flashpoint even our good old diesel.
For those who didn't know,
Flashpoint is the lowest temp that sufficient vapours occur to ignite with an ignition source.

petrol, Flashpoint -40 deg C
Diesel, Flashpoint 60 deg C

So diesel is by far safer as i cant remember the last day we had lower than -40deg C in Australia,
But dont think we don't get close to 60, ambient temp of 40 can easily become close to 60 under the right conditions, so as the diesel gets warmer (doesn't have to get to 60) thats flashpoint, it starts giving of more vapours = hydrocarbon fuel = heavier than air.

And here's some useless info but something you wouldn't think is so close together, the auto iginition temp for petrol is 350 to 450 deg C, and diesel is 335 deg C, so so diesel will auto ignite before petrol, not really relevant but thought i would share it with you.

Go Diesel whenever possible but don't think it is not possible to give of vapours as it does.
David.

[storm petrel]

Agree with all the above and second the motion that diesel is the way to go (if you can afford it).

Cheers,
Mark
'Storm Petrel'