350 MAG mpi 300hp/CM 225hp diesel

[Matt13]

Ed I'm not going to be tuning the engine just need to know if the stats I've linked to for the 225 look favourable and there is nothing that looks odd performance wise?

Many boats this size have a diesel option, so is the concern for this particular engine or diesels on this size boat in general?

[Gazjen]

Very big ship engines only rev to 800rpm....

Very very big ship engines only run to 100 rpm

Yes but they have a variable pitch prop, the engine speed stays constant.

The only real answer ask for a sea trial in both and see if you can live with the diesel as already stated it will be cheaper to run and safer, If you do that make sure you report back!

[markanddawn]

335d??[/quote]

C350 Cdi Sport

[Gazjen]

335d??

C350 Cdi Sport [/quote]

Owww Close, do I get a point for it being German? A friend of mine had a chipped 335d, 340 hp and 740 Nm of torque, very quick car for a diesel.

[markanddawn]

Yep, I'd love to chip mine although it voids warranty. If I owned it I would but it's a company car

You can have 1 point as I knew you'd go for 335d

Not as quick as your RS though

[Gazjen]

Yep, I'd love to chip mine although it voids warranty. If I owned it I would but it's a company car

You can have 1 point as I knew you'd go for 335d

Not as quick as your RS though

Nah it's only an S couldn't cope with the parts prices for the RS and that's being able to do it myself!

[baasboat1]

another factor for the petrol diesel debate, cost of red diesel may be going up so you need to factor that into your calculations. The EU arent happy that the UK have allowed red to be used in pleasure craft and have instigated proceedings against the UK to comply with the EU Directive, so within a year or so you can expect boats to have to use white diesel with the resultant costs increase. That could affect some marina retailers considering their position as they are unlikely to be able the infrastrcuture to sell both white and red - so they will probably pick the one they sell most off, which for the south coast will no doubt be white, but for the more remote provinces where commercial craft dominate it could well just be red only!
Also, another factor is the dreaded diesel bug, this willbe getting worse in the coming years as the percentage of biofuel has to increase significantly in diesel, that combined with reduced volumes being sold to boaters in the recession could lead to an increase in the bug from suppliers tanks to boat tanks, with the risks attached for us boaters.
The safetu aspect is of course another factor, the flashpoint of diesel is a lot lower than petrol and there are more risks associated with fueling and leaks inside boats - but keeping this is mind I can only recall one boat fire in thsi area in the last 17 years, and that was an electrical fault. So acknowledge the risk but place it in context of how many petrol boat fires happen in the UK each year. Of course if you do have the misfortune to catch fire (electrical cause most lilkely) it doesnt really matter whether you have petrol or diesel on board, once yhour fibireglass cathes fire your boats a gonner anyway.

In terms of fuel consumption, the 350mag will burn 24gph at WOT, 12gph at cruise and weighs 948lbs, whilst I dont have the VW data, CMD diesel sterndrives are:
QSD4 320hp - burns 19gph at WOT,and 12.7gph at cruise and weighs 1014lbs
QSD4 350hp - burns 21.5gph at WOT, cruise 13.9gph for the same weight

So a rough comparison, the petrol burns a few more gph at WOT but not much more at cruise, you will probably spend more time at cruise that WOT so not much of a difference there.

In summary, I would work out your estimated annual hours using burn rates at cruise speed and the current cost of petrol and white diesel, then multiply the difference by the number of years you are planning on keeping the boat, also factor in any difference in standard service costs. That may help your decision, along with how the boat feels in use of course!!

regards

Baasboat1

[Matt13]

Great advice thanks baasboat1! with the 225 V6 stats are:

rpm 1000 2000 3000 4200
gal/hr 0.4 0.8 4.6 13.4

Weight is 723 lbs

Im not sure on the diesel prices at the moment but I will include my MDL discount as well. I will have a go at working it out for 5 years of ownership and see what I get

[Gazjen]

It was £1.20 per l for diesel at the pump at cobbs while we were there (5,6,7th Aug)

They have already put the duty up on red diesel there is some kind of percentage for what's allowed to be brought for heating (They can't charge duty on it when used for heating) against fuel for propulsion, I believe it was around 70-30 % and most sell at this combined rate, on the river network anyway. There was talk at the time of my fathers tank at the front (For his Diesel stove) getting a lot bigger and accidentally feeding the rear tank

[Ed]

Very big ship engines only rev to 800rpm....

Very very big ship engines only run to 100 rpm

Yes but they have a variable pitch prop, the engine speed stays constant.

The only real answer ask for a sea trial in both and see if you can live with the diesel as already stated it will be cheaper to run and safer, If you do that make sure you report back!

True up to about 40,000 bhp but above that they have to be fixed. The engine I was speaking of (RTA96-C 14 cyl) is 108,000hp so has to run fixed prop. Has turbine driven prop and motor pods for manoeuvrability on the one I was shown about if I remember correctly

H

[JORIDAPILOT]

It was £1.20 per l for diesel at the pump at cobbs while we were there (5,6,7th Aug)

They have already put the duty up on red diesel there is some kind of percentage for what's allowed to be brought for heating (They can't charge duty on it when used for heating) against fuel for propulsion, I believe it was around 70-30 % and most sell at this combined rate, on the river network anyway. There was talk at the time of my fathers tank at the front (For his Diesel stove) getting a lot bigger and accidentally feeding the rear tank

The reduced rate of duty is for heating and lighting, therefore electricity generation is included, all engines have an alternator so even if you don't have heating you are still generating electricity for lighting so can claim a reduced rate, although not necessarily the 60/40 split. This is where it becomes a bit of a grey area.

What is the difference in price between the diesel and petrol engined boats? When I bought Jorida the cheapest diesel boat was literally £20K more which is fuel for umpteen years. You are used to the acceleration and performance of a petrol engine albeit an outboard on your Karnic so I would weigh up very carefully the overall costs over at least a 5 year life span.
There are not many diesel boats around the 25 foot length with good reason, and servicing costs seem to be so much higher for a marine diesel.

On the road I would go for a diesel car every time, but on the water there are so many more aspects to take into consideration.

[Centaur]

From the CMD stats, the VW motor will produce between 400Nm & 450Nm between 1,500-4,000rpm. The 350MAG will produce around 50Nm more across this range and hence will feel slightly more powerful. Furthermore, the 350MAG can rev to 4,800rpm, producing an additional 75hp, and will therefore have a significant top speed advantage.

The diesel will be best suited to steady running at relatively low cruising speeds. However, fuel consumption at low speed with the petrol motor will not be too horrific either so, unless you do significantly more than the average 50 hours / annum, you will not save a great deal of money on fuel. For most owners, the huge list-price premium usually placed on diesels over petrol motors, as JoridaPilot mentioned, simply outweighs the savings on boats up to and around 25'.

Bear in mind also that sports boats are often purchased for their performance rather than their cruising ability. The relatively modest performance of most diesel powered sports boats limits their appeal and therefore, unlike larger cruisers, they tend to suffer greater initial depreciation.

[Matt13]

From the CMD stats, the VW motor will produce between 400Nm & 450Nm between 1,500-4,000rpm. The 350MAG will produce around 50Nm more across this range and hence will feel slightly more powerful. Furthermore, the 350MAG can rev to 4,800rpm, producing an additional 75hp, and will therefore have a significant top speed advantage.

The diesel will be best suited to steady running at relatively low cruising speeds. However, fuel consumption at low speed with the petrol motor will not be too horrific either so, unless you do significantly more than the average 50 hours / annum, you will not save a great deal of money on fuel. For most owners, the huge list-price premium usually placed on diesels over petrol motors, as JoridaPilot mentioned, simply outweighs the savings on boats up to and around 25'.

Bear in mind also that sports boats are often purchased for their performance rather than their cruising ability. The relatively modest performance of most diesel powered sports boats limits their appeal and therefore, unlike larger cruisers, they tend to suffer greater initial depreciation.

Thanks for the advice Centaur and to all the others. Its been really helpful. Im pretty much decided now on petrol and am pretty sure which boat I would like. There is a 25' and 28' version, I could get the 28' one at the same price but slightly older. Thing is 28' even 25' is going to feel massive after my current boat!

[markanddawn]

Thanks for the advice Centaur and to all the others. Its been really helpful. Im pretty much decided now on petrol and am pretty sure which boat I would like. There is a 25' and 28' version, I could get the 28' one at the same price but slightly older. Thing is 28' even 25' is going to feel massive after my current boat!

1) What is the age difference
2) Are they in equally good condition/hours/service history/spec
3) What boat(s) are you looking at.

Go for 28', you'll wish you had once you're used to the 25 footer. It may prevent you needing to upgarde further for a while longer?

[Matt13]

Thanks for the advice Centaur and to all the others. Its been really helpful. Im pretty much decided now on petrol and am pretty sure which boat I would like. There is a 25' and 28' version, I could get the 28' one at the same price but slightly older. Thing is 28' even 25' is going to feel massive after my current boat!

1) What is the age difference
The larger ones on the market at the same price only seem to be a couple of years older than the 25 footers
2) Are they in equally good condition/hours/service history/spec
This is something I will check when I come to view
3) What boat(s) are you looking at.
That would be telling wouldnt it and where would the surprise be!?

Go for 28', you'll wish you had once you're used to the 25 footer. It may prevent you needing to upgarde further for a while longer?

Thats exactly what I am thinking as well regarding size