Reply
 
Thread Tools Search this Thread
 
Old 01 July 2006, 10:29   #1
Member
 
Country: Sweden
Town: Stockholm
Make: KR7
Length: 7m +
Engine: Evinrude 150 H.O
Join Date: Aug 2005
Posts: 735
Fueleconomy 175-250 hp.

If you have a 250 on a rib and a 175-200 on another. If you will drive the same distance with both boats and the same speed. Most of the time will be cruising speed.

And if you don´t drive faster with the 250 than the 175-200. What will the difference in fueleconomy be?

(Do you understund?)
__________________
joakimhansson is offline   Reply With Quote
Old 01 July 2006, 13:07   #2
Member
 
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
I think I know what you mean.

It all depends on throttle settings - if the 175 needs say 5000rpm to keep up with the 250 running at 4000rpm then prob the 250 will use less fuel.

Having said that so much depends on engines - props etc etc.

It seems to me most people with big RIBs get roughly the same sort of fuel economy no matter what big engine they are using.
__________________
codprawn is offline   Reply With Quote
Old 01 July 2006, 23:16   #3
Member
 
Country: UK - England
Boat name: SOLD
Length: under 3m
Join Date: Jun 2004
Posts: 794
We have a Yamaha 250 Four/stroke dose appox 1.25 lts to the mile at approx 5000 RPM
__________________
Roy Smith is offline   Reply With Quote
Old 01 July 2006, 23:18   #4
Member
 
Country: UK - England
Boat name: SOLD
Length: under 3m
Join Date: Jun 2004
Posts: 794
Just a thought next week weather permtting there is a cruise to Alderney
would be good to see what people are getting in the real world
__________________
Roy Smith is offline   Reply With Quote
Old 02 July 2006, 11:25   #5
Member
 
MarkM's Avatar
 
Country: Netherlands
Town: Breda
Make: Scorpion
Length: 7m +
Engine: Evinrude 250 DI
Join Date: Oct 2003
Posts: 368
I did a bit of a study on this for months.

On the back of the Scorpion 7,5 I had an Evinrude 150 Ficht. At 3750 rpm it did 50km/hr with 32 liter/hour. At 5000 rpm, 60km/hr, 53l/hr.

Later I changed to an Evinrude 250 DI:
At 3500rpm also 50km/hr with 32 l/hr.
At 4000rpm, 60km/hr, 40l/hr.

As you can see the 150 was too light for this boat. With the 250 at 60km/hr it's 13 liters per hour cheaper. At WOT it is not 85 l/hr, but with 98km/hr .
I'm very happy with the change. Especially in the rough it takes less fuel to get over the waves or against the tide.
__________________
MarkM is offline   Reply With Quote
Old 02 July 2006, 14:15   #6
Member
 
Country: Sweden
Town: Stockholm
Make: KR7
Length: 7m +
Engine: Evinrude 150 H.O
Join Date: Aug 2005
Posts: 735
Yes More expensive to buy but cheaper to drive. The noiselevel must be much better to....

Yes...now i can tell my girlfriend that we "need" a 250 on the rib.
__________________
joakimhansson is offline   Reply With Quote
Old 02 July 2006, 15:22   #7
Member
 
MarkM's Avatar
 
Country: Netherlands
Town: Breda
Make: Scorpion
Length: 7m +
Engine: Evinrude 250 DI
Join Date: Oct 2003
Posts: 368
With the 150 most of the time I was traveling in the 5000rpm range. Now with the 250 it's more the 3500 to 4000rpm range.
The orange line shows the range with an amount of fuel. The higher the figure, the further the distance you can travel with that amount of fuel. Ofcourse at 1000rpm you get very far but it takes ages; at around 4000rpm you travel very economically with a reasonably speed.
Attached Thumbnails
Click image for larger version

Name:	verbr.range.Evnr250.jpg
Views:	337
Size:	77.5 KB
ID:	20448  
__________________
MarkM is offline   Reply With Quote
Old 04 July 2006, 10:30   #8
Member
 
Hugh Jardon's Avatar
 
Country: UK - England
Town: Reading, Hants
Boat name: Juicy
Make: Sealine F43
Length: 10m +
Engine: 2 x 370hp
MMSI: TBC
Join Date: Sep 2005
Posts: 2,884
my opti 200 on the vipermax 6.5 seems to be working out superb with an overall average from the smartcraft of 4.4 miles per usa gal. on sat in pwilly we used 61 quid of fuel, this was the same as some smaller boats with 80 hp fourstokes and less than some boats with 115 fourstrokes. Brad used similar fuel with his 100 hp

really chuffed and my initial concerns about how much fuel we would use have gone away. And, it is probably fair to say that we dont exactly drive economically!! the new prop has increased my fuel mpg!!

very happy all round and would defo recommend an opti
__________________
Hugh Jardon is offline   Reply With Quote
Old 04 July 2006, 18:33   #9
Member
 
Country: UK - England
Town: Macclesfield
Boat name: Aqua Fresh
Make: Zodiac Medline
Length: 5m +
Engine: 60hp Yamaha
MMSI: 235051988
Join Date: Feb 2006
Posts: 333
how much !

god my engine must be using some fuel then as i used 35l on saturday and iknow that you went further as you went over to the islands at abersoch
30hp at 25mph 4800-5000rpm 35l on trip not sure of distance
__________________
floater is offline   Reply With Quote
Old 04 July 2006, 18:41   #10
Member
 
Hugh Jardon's Avatar
 
Country: UK - England
Town: Reading, Hants
Boat name: Juicy
Make: Sealine F43
Length: 10m +
Engine: 2 x 370hp
MMSI: TBC
Join Date: Sep 2005
Posts: 2,884
Quote:
Originally Posted by floater
god my engine must be using some fuel then as i used 35l on saturday and iknow that you went further as you went over to the islands at abersoch
30hp at 25mph 4800-5000rpm 35l on trip not sure of distance
i filled mine to the brim on friday and then filled it to the brim again on sunday morning before we went out for a bit of a spin so that is an accurate fuel usage

our speed varied up to around 50 plus on both days with quite some time spent at the higher throttle settings
__________________
Hugh Jardon is offline   Reply With Quote
Old 04 July 2006, 22:26   #11
Member
 
Country: UK - England
Town: Clitheroe
Length: no boat
Join Date: Mar 2006
Posts: 77
Yes i remember talking to you about that, were at WOT all he time pretty much. During the weekend we had her fully trimmed out at full power all the way, just touching 31 knots. This probably explains the poor fuel comsumption.

Whats sort of RPM were you at most of the time and WOT speed?
__________________
Alex-341 is offline   Reply With Quote
Old 04 July 2006, 23:33   #12
Member
 
Country: UK - England
Town: hants
Boat name: Viper
Make: Osprey Vipermax 6.5
Length: 6m +
Engine: 200 opti
MMSI: 235 036 257
Join Date: Dec 2005
Posts: 74
Quote:
Originally Posted by zodiac rover
Yes i remember talking to you about that, were at WOT all he time pretty much. During the weekend we had her fully trimmed out at full power all the way, just touching 31 knots. This probably explains the poor fuel comsumption.

Whats sort of RPM were you at most of the time and WOT speed?
for us wot is around 47knots / 53-54 mph at around 5400 rpm but i can not swear to the rpm as never looked close enough when zipping along. the speed most folks seems to be doing was around 40 -45 mph at the front and we spent a good bit of time going reasonably fast with spurts of wot. I guess we were cruising anywhere around 35-50 mph as we would change position in the pack. we would look for wakes to jump and play around which would cause us to change position quite a lot.

i think our economy is down to the engine reasonably effortlessly pushing the boat along. when on the plane and it has a planing pad it is very easy going. Some of the smaller engines were at wot most of the day i suspect and this is never a good economical approach.

so for me the day was even more enjoyable knowing we had only burnt a reasonably frugal amount of fuel as fuel consumption was a big concern of mine prior to the purchase of the engine. i was really pleased to return fuel consumption better than or equal to smaller 4 strokes.

i can honestly say i love my opti lots

using the mrs pc here

chris
__________________
Im in my own world most of the time, but its ok as they know me there. Debs x
Mrs Jardon is offline   Reply With Quote
Old 05 July 2006, 11:55   #13
Member
 
Country: UK - Wales
Town: Southampton
Boat name: DynaMoHumm/ SRV/deja
Make: Avon8.4, 5.4 & 4.777
Length: 8m +
Engine: Cat3126 Yam 90 &70
MMSI: 42
Join Date: Dec 2003
Posts: 6,562
you do get a lo of bang for your buck with an Opti
__________________
Here it comes again, I don't stand a chance
Soul possession, Got me in a trance
Pullin' me back to you - Deja Voodoo
Rogue Wave is offline   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




All times are GMT. The time now is 21:33.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.