What size does Diesel become viable

[peteb]

Just wandering what size you feel would justify the additonal expense of a diesel engine.

[thewavehumper]

I was allways told it was about 7 metres plus, but I've seen a couple of 6.5's and the owners say they work fine. the new mercruiser lightweight diesel seems to be quite popular in a smaller boat

[Andre]

Originally posted by peteb
Just wandering what size you feel would justify the additonal expense of a diesel engine.

Size is not the only thing you must consider but also what is the main purpose of having a diesel boat (rib)

Do you just want to go out ever so often for a spin to Cowes and back or serious ribbing like a weekend trip to France or the Channel Islands. If the latter then yes a diesel engine is the way to go

I hv a 6.3 rib with a Mercruiser 1.7 TDI and since a lot has already been said about this engine I suggest you do a search and read some of the previous threads and learn what has been already said about this particular engine and set up.

I keep my rib in Littlehampton and frequently venture out to Cowes/Yarmouth. The cost of diesel for such round trip is only about £20.00 (this is a distance over 80 miles)
Only last weekend I had a conversation with a chap who has a 6 mtr cabin cruiser with a Volvo Penta 140 HP petrol engine. He told me a trip to Brighton and back would cost him about £ 60.00
He also said he would have liked to have a diesel as this would allow him to go out more often and even make longer passages

Andre

[peteb]

I have been looking at a Volvo 5.0Gxi dp, but also looked at the diffenece in price between the standard 5.0GL and a KAD32, the difference was £9,300. I was really amazed and have been trying to calculate a 'break even' point, but in the end decided that there would be a number of factors as you say to take into account to make it worth while. It is a lot of money to recoup, and a bit of loss to performance I would think.

[DGR]

There was a thread earlier on this week about a trip to France, which cost £33 in diesel opposed to £100+ for petrol, so I agree with Humper and Andre!!

It seems to be about what you want to do with your boat!! I want a reasonable performance when required, but also want to be able to go on long-ish cruises without breaking the bank. 6.5+ (ish) appears to be the break-even, but I'm still having problems getting my mind around the cost of a new 'big diesel' RIB. One manufacturer (of several I've asked for quotes) has more than doubled their quote from the website (27k to 55k+) - and the only extras I asked for were an A-frame, 2 extra seats, and an big diesel!! Oh, and craning points.

By the way, I have a honking great big diesel engine in my Land Rover...but the V8 petrol version was more...... why is that?

D...

[chrisallse]

Good point DGR, dont see why a basic inboard deisel should be that much more than a modern high tech compact outboard.

[peteb]

Thanks to all for the input, as you have mentioned it seems strange that diesel engines are so much dearer than petrol, I guess they are exploting the diesel v petrol fuel price 'while they can'. What concerns me is if the fuel price was the same or similar would I still want a diesel, I think the answer would have to be no, I would want petrol.

I would think that if the prices become similar there could be a bigger rise in the use of petrol boats and a decline in diesel, with more petrol becoming available at the pumps.

The only downside seems to be cruising range, but for some left with massive diesel engines, I think they msy struggle financialy to go cruising long range anywhere with diesel at petrol prices anyway.

[PeterL]

I wish someone could answer all these questions.
as everyone has said, it all depends on what you want out of the said rib.
I have been in the same dilema, but looking long term and not wanting 50+ mph, the diesel is the way to go.

6 to 6.5 m and the general view is 1.7 mercruiser, over this and then you are looking at 7 m with Yanmar etc..

Give Jason a call at Ribcraft, they seem to be very competitive in this area.

[Austen]

Morning all,

with diesel at petrol prices anyway

Please don't quote me on these figures, my sources may be out of date, but the theory will be the same, if I'm wrong, please feel free to correct me.

The price of Marine grade diesel (Red Diesel) should always be significantly cheaper than any Petrol available (legitimately) in the UK.

There is very little tax on Red Diesel (in 2001, this was 3%) compared to "normal" diesel (2001 45% /2003 75%). That's about £ 0.3552 p/l against £0.7779.

Based on this alone, it should ALWAYS be cheaper to run a diesel!

austen...

[Richard B]

Originally posted by Austen

unfortunately not. http://rib.net/forum/showthread.php?...derv#post30800