what ought a pair of 200hp volvo turbos diesels do fule wise?

justdrifting

justdrifting

Well-Known Member
Joined
3 Dec 2007
Messages
86
Visit site
Ive wanted to ask for some time.I always "intend" to log the fule x hours x miles but never do.

The log gave up when i came aboard,ive never had a working log other than when i used a "walkers" trailing log even on that the speed dial gave up very quickly because the glass wasent sealed!

I have a Bertram 28 (not mine im just using her for now)she has a pair of 200 hp Volvo turbo diesels

I use a Garmin 152 for speed & distance it indicates my speed around 22 knots at 3000 rpm 24/5knts at 3600 and 21 /22knts at 2900 rpm!

Ive just topped up they seem to be running well(fule use wise) running very well dont miss a beat and sound great in sync.

How much fuel "should" she use at cruise say 18/20 knots how much flat out and how much at say just planing speed?

She always seems to use the same amount? I tend to leave the anchorage with the intention of not passing 2600rpm but within a moment im at 2900rpm then 3200rpm then back to just less than 3000rpm as the sound feel is very good

What "should my fule consumption be?

P.S merry christmas

That is an a calm sea
 
Hi I had a fairline corniche same engines on shafts at 3100rpm I got 21/22 knots on gps fat out 3900 30 plus depending on tide with clean bottom, never ran it much below 3000 as its turbos were not boosting enough to burn all the fuel, it averaged 1.72 mpg over 5 tank fillings last year on my holidays.

Hope that helps and merry christmas!
 
There are various ways of estimating fuel consumption at various rpm. Obviously, you can do this by filling the tanks, going for a (lengthy) test run at a constant rpm, recording the distance covered and then brimming the tanks again but this takes a lot of time.
But the quickest way you can estimate fuel consumption is by getting hold of the engine manufacturer's power and (better) fuel consumption curves. If you have the latter, you can read off the fuel consumption at a particular rpm and knowing the speed your boat achieves at that rpm, you can calculate the mpg at that rpm. Sometimes it's not possible to get a fuel consumption curve for a particular engine but you can get a power curve. Diesel engines generally have a specific fuel consumption (SFC) of about 175-200 grams per KW hour. If you know the speed that the boat achieves at various rpm you can calculate fuel consumption in mpg using the SFC but this is less accurate than having the actual manufacturer's fuel curve
Whatever you come up with, remember that fuel consumption will increase significantly in rough seas or if the boat's hull or sterngear is fouled
 
Nice data and realy useful. Interesting to see what their D6-350 engined Scirrocco 33 gets speed and fuel use wise.

Thing is, these figures are all for the latest common rail direct injection motors - 20 year old AD41's (which is what the Bertram has) will be way off the pace interms of efficiency. I have noticed a big difference on the D4's vs the older KAD 43's, and that is only a difference of ten year in developement, not 20.

Useful find all the same.
 
Its never going to be an exact science on the older Engines,But I would go with Volvopaul on this one, I get about the same, give or take out of my AQAD41s (Sealine 305)
 
my Boat has 2 x 200 HP Volvo Aqua 41 with stern drive duoprop from 1994
consumption is about 40-50 LPH at 2900 / 3100 RPM
speed is about 22 - 26 knots
I think the most efficent speed is 3000 RPM 24 knots

the 41s on shaft rev a maximum of 3500 instead of the 3900 on sterndrive if I am remember correct...
 
You must log in or register to reply here.

Share this page

Top