Diesel vs Petrol 2011!

ricky_s

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Now that diesel is so expensive, taking into consideration the diesel bug. Would we now be better off going for a petrol boat?

Having to keep the tanks full is expensive on diesel boats plus extra weight, probably two engines to have enough power, surely petrol is the way to go!
 

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No!

Well, it depends on size of the boat.

I think the changeover point where petrol makes sense has got a bit higher, so a 24ft boat with a single petrol now makes sense if you aren't going too far, and can get hold of petrol, but having two V8 petrols in a 28-30ft boat is still going to produce some very scary fuel consumption figures.

16 cylinders would sound good though!
 

ricky_s

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No!

Well, it depends on size of the boat.

I think the changeover point where petrol makes sense has got a bit higher, so a 24ft boat with a single petrol now makes sense if you aren't going too far, and can get hold of petrol, but having two V8 petrols in a 28-30ft boat is still going to produce some very scary fuel consumption figures.

16 cylinders would sound good though!

What about two 28 foot boats, one with a single v8 petrol and another with two D3 diesels?
 

joliette

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I think you need to think about the total engine purchase, servicing and fuel consumption costs, to make a decision. Petrol engines costs considerably less then diesel and are generally cheaper to service /maintain. Petrol engines are a serious consideration, now that the gap between petrol and diesel fuel prices has closed.

My project:http://www.facebook.com/home.php?sk=group_179427293999&ap=1
 

Geoffs

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Now that diesel is so expensive, taking into consideration the diesel bug. Would we now be better off going for a petrol boat?

Having to keep the tanks full is expensive on diesel boats plus extra weight, probably two engines to have enough power, surely petrol is the way to go!

If I had my time again, I'd still go for diesel on the old 240. OK up front cost is more, and probably won't get it all back come resale.

I do about a litre a mile, there is a psycomalogical effect, you forget the extra capital cost when you fill up. It's getting expensive now, but not as much as petrol.

Lot's of other benefits. More relaxed cruising. Engine a gentle purr at 25knots and 2500 rpm. Fuel more available, but we've been through all this before.

DIESEL EVERY TIME.
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PCUK

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Petrol not easily available anywhere except the south coast. So basically a non starter. Can't understand the nonsense about petrol engines being cheaper to service. They both need oil and filters, diesels don't need plugs changing every year so where is the extra service expense?
 

Fire99

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Having had a petrol V8 powered 23ft boat, i'd still go with diesel, even at that size.
On the east coast, availability is the issue. OK you can fill up 20l cans at some petrol stations but lugging them to the boat every time you go out, is a pain in the backside.

Yes the engine was as complicated as a lump of stone and it sounded nice but the hassle and limited range (you could go somewhere but there would be no petrol available there to get you back) would put me off doing it again.
 

Seahope

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Now that diesel is so expensive, taking into consideration the diesel bug. Would we now be better off going for a petrol boat?

Having to keep the tanks full is expensive on diesel boats plus extra weight, probably two engines to have enough power, surely petrol is the way to go!

I know I shouldn't worry about it (since I have driven petrol cars for 30 years or so without a problem), but personally I would worry too much about the risk of fire / explosion in a petrol boat to fully enjoy my boating.
 

ricky_s

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I know I shouldn't worry about it (since I have driven petrol cars for 30 years or so without a problem), but personally I would worry too much about the risk of fire / explosion in a petrol boat to fully enjoy my boating.

Do they ever really explode though?
 

lovezoo

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Do they ever really explode though?
There was a fire in the boatyard where I keep my boat, which totally destroyed the workshop and badly damaged the boat parked next to it. Despite what we are lead to believe, no boats exploded in the fire.

The main risk of explosion in a petrol engined boat is from a build up of petrol fumes in the engine bay. This is why it is important to turn the blowers on for a few minutes before starting, to vent the bay. You can also get alarms which will go off if they detect petrol vapour, or automatically start the blowers.

The same risks apply to gas bottles on boats - how many diesel powered boats have them?
 

joliette

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Can't understand the nonsense about petrol engines being cheaper to service. They both need oil and filters, diesels don't need plugs changing every year so where is the extra service expense?

Assuming you have a classic carb petrol engine, then the additional servicing and maintenance costs in a modern diesel are in the fuel injection system, turbocharger and ECU. Repairing such items is usually beyond the scope of the amateur mechanic and sealed ECUs just have to be replaced with new items costing ££££. These issues do not arise in a classic petrol engine.
 

Sneds

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I have a 28 ft sports crusier with twin diesels, wouldn't go back to a petrol engine for love or money.
Water and ignitions don't mix!
 

Andrew_Fanner

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Assuming you have a classic carb petrol engine, then the additional servicing and maintenance costs in a modern diesel are in the fuel injection system, turbocharger and ECU. Repairing such items is usually beyond the scope of the amateur mechanic and sealed ECUs just have to be replaced with new items costing ££££. These issues do not arise in a classic petrol engine.

Tha's OK, I have "classic" diesel engines. No ECUs there either:)
 

ulyden

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Modern diesel engines often are parent bore common rail turbocharged and have a intercooler.

With common rail you are dependent on a set of sensors that senses speed, rail pressure, crank position, boost pressure.

You also have actuators/control signals for setting the rail pressure and open the injectors in correct timing.

Some diesel engines also have waste gate turbochargers and even variable turbine geometry.

That means the diesel engine is more complex to maintain and handle. The parts are expensive and the lifetime is limited in sea water environment.

Most petrol engines are cheap American engines. Spare parts are cheaper and number of components is less.

Engine blocks are cheap and it’s possible to rebore cylinders.

The reliability is quite equal comparing a modern common rail with modern petrol. Number of components that can stop the engine is more or less the same.

Modern diesels are consuming the same amount of fuel as older direct injected diesels take or give 5%.

Petrol engines aswell. The difference in fuel cost is there 20-30%.

Try to link in to test on winy boats comparing D3 with petrol engines. At speeds between 25-35knots the difference is not big!

Well main concern is repair and maintenance cost. Modern diesels have expensive injectors, turbos, coolers , electronics
and sensors/actuators.
If you have a modern diesel with a outdrive the cost is so high that people refuses to buy it when its 5-10years old.

On a petrol the torque is lower the parts are cheaper and maintains is easier.

http://www.windy.no/downloads/28_GHIBLI_2_4_3_GXI_ DP_S_gear_ratio_1_95_1.pdf

http://www.windy.no/downloads/28_GHIBLI_2x4_3_GXI_DP_S_gear_ratio_1_95_1.pdf
 

CX54WEK

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Diesel every time.

The fuel costs less (ours is currently 88ppl), it uses less and it is avaliable pretty much wherever we go. Servicing of the engine isnt hugely expensive, ours is a fairly simple lump (KAD32) and is proving to be pretty much bomb proof.

We wouldnt even consider a petrol boat. Yes they are cheaper to buy but with the annual useage that we do (about 300 hours) we couldnt even consider the extra fuel bill, let alone the worry of getting fuel at our destination and then the worries about reliability. As has already been mentioned water and petrol ignition systems dont mix. The yank petrol engines may be relatively cheap to buy and replace but a well maintained diesel wont need replacing.
 
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