Diesel, Petrol and Gas

[Glyn-2008]

I've always thought that I knew why the larger petrol propelled boats were often for sale at a lower price than their Diesel powered sisters. I've heard the stories of fuel costs, water and ignition systems etc. However, at the weekend we were moored next to a very nice couple who owned a Princess 330 who had arrived in the very early morning almost silently (especially in comparison with our Volvo diesels). The owners had re-engined the boat with twin 316hp petrol engines and had the ability to run them on gas. I would have thought that they may have considered diesel engines but they had a fairly convincing story for sticking to the petrols. They claim that the Gas (whilst not available everywhere) costs in the region of 70p per litre and if not available they can always switch back to petrol. Also, that the diesel bug was not an issue, nor would they offend any Belgian official on the lookout for red dyed fuel should he venture Eastwards.
Does anybody know if a diesel engined boat would travel further on a litre of fuel in comparison to a litre in the tank of a petrol driven boat as per our cars? Also would a litre of gas propel the boat for the same distance as a litre of petrol? So what are the other plus and minus points?

 

[Philiz]

I don't know about the consumption comparisons, but there are precious few sources for buying petrol let alone LPG.

I don't think I'd fancy it parked next to me

 

[gjgm]

I've always thought that I knew why the larger petrol propelled boats were often for sale at a lower price than their Diesel powered sisters. I've heard the stories of fuel costs, water and ignition systems etc. However, at the weekend we were moored next to a very nice couple who owned a Princess 330 who had arrived in the very early morning almost silently (especially in comparison with our Volvo diesels). The owners had re-engined the boat with twin 316hp petrol engines and had the ability to run them on gas. I would have thought that they may have considered diesel engines but they had a fairly convincing story for sticking to the petrols. They claim that the Gas (whilst not available everywhere) costs in the region of 70p per litre and if not available they can always switch back to petrol. Also, that the diesel bug was not an issue, nor would they offend any Belgian official on the lookout for red dyed fuel should he venture Eastwards.
Does anybody know if a diesel engined boat would travel further on a litre of fuel in comparison to a litre in the tank of a petrol driven boat as per our cars? Also would a litre of gas propel the boat for the same distance as a litre of petrol? So what are the other plus and minus points?

The theme was popular maybe 7 years ago but ran into two obstacles.
Conversions for petrol engines was expensive and for whatever reason, unreliable. Secondly, as regards coastal boating, the few dedecated refilling locations dried up.
So, even if you had a super price efficient boat, if you couldnt go anwhere bcz you couldnt refuel... well, it all rather fell apart.
It might be there are some efficiencies IF you keep you boat on a some narrow stretch of inland/coastal water, but the resale price of your boat become seriously compromised, surely?

 

[Glyn-2008]

[So, even if you had a super price efficient boat, if you couldnt go anwhere bcz you couldnt refuel... well, it all rather fell apart.
It might be there are some efficiencies IF you keep you boat on a some narrow stretch of inland/coastal water, but the resale price of your boat become seriously compromised, surely?[/QUOTE]

I'd always assumed that petrol was available on marinas for the sportsboats up to 24ft ish ( it was at Sparkes Marina on Hayling Island) but, come to think of it, they're often on trailors filling up at roadside petrol stations. Looking at boats for sale , it would appear that the resale price of the boats fueled in this way IS compromised. The Princess had been able to travel along the solent to Bembridge so they must have found fuel somewhere. The boat was quieter and not at all smokey like mine. In line with the previous reply to my post, I did not consider the fact that I had a possible incendiary device rafted outside me at the time. Should boats be marked with DERV or petrol as a warning?

 

[Nick_H]

Smoke is not much of an issue with modern diesel engines, so if re-engining there's even less reason to choose petrol. As gjgm says it could possibly work in terms of running costs if you have a restricted cruising area within reach of a gas pump, but any gains will be lost for sure when you come to sell the boat.

 

[dustywings]

I re-engined my boat from petrol to diesel, the petrols were V8 7.4l 350hp and at cruising speed used 110 litres per hour. The diesels which are 300hp at the same cruising speed use 66 litres per hour so a big difference plus of course that diesel is cheaper to buy with the 60/40 split. The V8s did sound good though!!

 

[Glyn-2008]

I re-engined my boat from petrol to diesel, the petrols were V8 7.4l 350hp and at cruising speed used 110 litres per hour. The diesels which are 300hp at the same cruising speed use 66 litres per hour so a big difference plus of course that diesel is cheaper to buy with the 60/40 split. The V8s did sound good though!!

Regardless of how good they sounded it was costing you £150 + per hour at best, that is frightening. Mind you, £66+ per hour would not encourage me to travel very far from home either. I used to wonder why people re-engined their boats with the huge costs involved but we have become attached to ours and would do the same if necessary, however cost effective that would be (or not). Boating is no longer a financial investment of any description but the pleasure derived from it is plentiful.

 

[rafiki_]

Glyn, a rough estimate for the same hull/weight/weather etc would be, 1 litre of diesel = 1 km, 1 litre petrol = 0.6 km, and 1 lite of gas = 0.5 km. It is all to do with relative efficiency, and energy density of the fuel.

 

[Glyn-2008]

Glyn, a rough estimate for the same hull/weight/weather etc would be, 1 litre of diesel = 1 km, 1 litre petrol = 0.6 km, and 1 lite of gas = 0.5 km. It is all to do with relative efficiency, and energy density of the fuel.

Thanks rafiki, Thats the answer to the main question then. Gas, even at 70p per litre is still much more expensive than diesel as it will take £1.40 worth of gas to travel the same distance as £1.04 worth of diesel. Apart from that there is the availability and flaspoint issues of Gas / Petrol..
Aside from visiting Belgium and risking the diesel bug on the neg side for diesel, it would appear to be the fuel of choice..
nuf said.

 

[rafiki_]

There are others benefits with diesels, including the availability of fuel, residual value of the boat, and ease of sale. Mind you, petrol is probably the most common fuel for boats 25" and shorter.