Best Fuel economy?

liluoke · 08-27-09, 12:04 PM

How do you achieve best fuel economy with the sub?

Standard propulsion + what speed? Ahead standard? Ahead flank apparently burns more fuel (just like driving your car too fast.. haha)

Anything else that may conserve fuel for a trip back to port?

Sorry if this is a repost.

teg916 · 08-27-09, 12:24 PM

The slower you go the less you burn. Try experimenting by setting a speed and asking your navigator for max range at current speed.

derrinurban · 08-27-09, 12:36 PM

I just follow the slower is more efficient philosophy. I am sure someone here has some hard numbers. When heading back to port (all torpedo's spent), I normally plot the course, then ask the NO for distance to end of plotted course and maximum distance at current speed. then adjust my speed to get me there the quickest while not running out of fuel.

I did actually have one mission where I was running so low on fuel that I had to run submerged at ahead slow (best use of batteries) till the batteries were drained, surface and run at ahead slow (order the CE not to recharge the batteries) and barely made it.

DU

FIREWALL · 08-27-09, 12:49 PM

Weather is an issue too.

Fishers of Men · 08-27-09, 01:53 PM

I will set diesel engines to 7 knots, in my type VII boat, for maximum range. But in rough seas, you will need to use more fuel to keep moving ahead at that pace. I will set the telegraph to 8 knots to achieve a 6-7 knot speed. On a smooth ocean, you can save quite a lot of fuel and extend your range.

FoM

gordonmull · 08-27-09, 01:55 PM

There is an optimal speed for each u-boat type but I can't remember what they are. Going too slow seems ineffiecient as well as going too fast. Think there's a mod somewhere that sets ahead one-third as your optimal speed for fuel economy for each boat. Anyway, I just use one-third because as far as I can remember its as near as verdamt.

liluoke · 08-27-09, 02:00 PM

i see, good points!

i think going TOO slow will also be a waste of fuel, there has to be an optimum speed somewhere in between, i'll figure it out with the range button and let you guys know...

lol i remember in das boot bad weather makes you burn a lot of fuel, should I go to periscope depth and try to ride out the storm like in the movie? =p

gordonmull · 08-27-09, 02:16 PM

Save yourself the hassle! Here is a thread which should have what you're looking for.

http://www.subsim.com/radioroom/show...ght=speed+fuel

Brer Rabbit · 08-27-09, 03:14 PM

I make frequent use of the resupply ships, ie greenland, Portgual and spain, and plan my routes and patrols accordingly.

Happy Hunting

Pohl · 08-27-09, 03:29 PM

aim for 8 knots, in a Type IXD2 I get a fuel economy of 106,XXX km, on the Type XXI I get 55,XXX km

KeybdFlyer · 08-27-09, 05:37 PM

Get yourself a nice, flat calm day (0 mt/s). Select speed by actual knots, not "Standard, ⅔ etc). Try from (say) 6 kts to 10 kts and each time the speed has settled check with your NO "Max range at current speed". You'll soon find the optimum speed for maximum range for the type of boat you're in.

ORrrrr... just d/l and install WB's Decks Awash mod that adjusts the setting for "Ahead ⅔" to give the best economy by default and sets the "Snorkel depth" command to give you decks awash by default (can be removed later when you get one fitted). I was in the process of doing exactly what WB had already done when I came across his mod - so in a fit of pique I checked all his settings in-game and guess what? He got 'em right, lol.

Captain Nemo · 08-28-09, 07:22 AM

Generally speaking I find 8 knots to give the best fuel efficiency. I am currently attacking a convoy heading for Halifax about 500 kilometres off the Canadian coast in my type VIIB and have still got over half a tank of fuel left. Might use the Belchen supply ship stationed on the Greenland coast on the way back though.

Nemo

sharkbit · 08-28-09, 08:08 AM

Quote:

Originally Posted by derrinurban

I just follow the slower is more efficient philosophy.

That is not necessarily true. On average, depending on sub type, 7-8 knots is most efficient. The range falls off if you go slower or faster than that.

What I usually do when I get a new type of sub, if the weather is good, I'll check the range settings at each engine telegraph position(along with speeds) and also at various knot settings to find that sweet spot. I have them recorded on a spread sheet for future reference.

irish1958 · 08-28-09, 02:58 PM

This was a concern in developing GWX. The ranges of the U-boats were tuned to be (on the average) the normal ranges for each boat at ahead standard. Sea state has a major effect on fuel economy. (and in real life, so does wind, ocean streams and circulation, quality of oil, state of the engine, etc.)
Using the battery doesn't help, as recharging requires one engine to run to supply the energy to run the generator. I am not sure of this, but I suspect it would worsen markedly your range as pushing an U-boat against the resistance of sea water as opposed to air should increase the forces necessary to move the boat.

09-23-09, 02:04 AM

I just follow the uboat commanders handbook which states, the default patrol speed is Slow. Those other speeds are just for certain situations that may arise. It works. The most important thing you can do to keep your range high is NOT upgrade your diesels. The upgrade makes for unrealistic speeds anyway. Try it any way you like. My IXB always makes it back from Capetown, without refueling. Unless I sunk. Don't like those Capetown patrols. IXCs and IXD2s are better suited to that area. Long long ride.

08-27-09, 12:04 PM	#1
liluoke Swabbie Join Date: Aug 2009 Posts: 10 Downloads: 8 Uploads: 0	Best Fuel economy? How do you achieve best fuel economy with the sub? Standard propulsion + what speed? Ahead standard? Ahead flank apparently burns more fuel (just like driving your car too fast.. haha) Anything else that may conserve fuel for a trip back to port? Sorry if this is a repost.

08-27-09, 12:49 PM	#4
FIREWALL Eternal Patrol Join Date: Mar 2006 Location: CATALINA IS. SO . CAL USA Posts: 10,108 Downloads: 511 Uploads: 0	Weather is an issue too. __________________ RIP FIREWALL I Play GWX. Silent Hunter Who ???

08-27-09, 01:53 PM	#5
Fishers of Men Seaman Join Date: Apr 2009 Location: Fishers, Indiana Posts: 37 Downloads: 106 Uploads: 0	I will set diesel engines to 7 knots, in my type VII boat, for maximum range. But in rough seas, you will need to use more fuel to keep moving ahead at that pace. I will set the telegraph to 8 knots to achieve a 6-7 knot speed. On a smooth ocean, you can save quite a lot of fuel and extend your range. FoM __________________ I am a monster from the deep.........the destroyer of my enemies.

08-27-09, 03:14 PM	#9
Brer Rabbit Briar Patch Runner Join Date: Oct 2007 Location: Tucson, AZ Posts: 95 Downloads: 89 Uploads: 0	Resupply I make frequent use of the resupply ships, ie greenland, Portgual and spain, and plan my routes and patrols accordingly. Happy Hunting

08-27-09, 03:29 PM	#10
Pohl Sparky Join Date: Apr 2009 Posts: 157 Downloads: 31 Uploads: 0	aim for 8 knots, in a Type IXD2 I get a fuel economy of 106,XXX km, on the Type XXI I get 55,XXX km __________________ Current Careers: U-177 Type IXD2, 10th Flotilla March 13, 1943 U-3502 Type XXI, 7th/13th Flotilla April 14, 1942 100% realism, GWX 3.0, SH3 Commander 3.2

08-27-09, 12:24 PM	#2
teg916 Watch Join Date: Aug 2009 Location: California Posts: 27 Downloads: 0 Uploads: 0	The slower you go the less you burn. Try experimenting by setting a speed and asking your navigator for max range at current speed.

08-27-09, 12:36 PM	#3
derrinurban Mate Join Date: Aug 2009 Location: Calgary, Alberta, Canada Posts: 54 Downloads: 33 Uploads: 0	I just follow the slower is more efficient philosophy. I am sure someone here has some hard numbers. When heading back to port (all torpedo's spent), I normally plot the course, then ask the NO for distance to end of plotted course and maximum distance at current speed. then adjust my speed to get me there the quickest while not running out of fuel. I did actually have one mission where I was running so low on fuel that I had to run submerged at ahead slow (best use of batteries) till the batteries were drained, surface and run at ahead slow (order the CE not to recharge the batteries) and barely made it. DU

08-27-09, 01:55 PM	#6
gordonmull Lieutenant Join Date: Apr 2005 Location: Scotland Posts: 269 Downloads: 20 Uploads: 0	There is an optimal speed for each u-boat type but I can't remember what they are. Going too slow seems ineffiecient as well as going too fast. Think there's a mod somewhere that sets ahead one-third as your optimal speed for fuel economy for each boat. Anyway, I just use one-third because as far as I can remember its as near as verdamt.

08-27-09, 02:00 PM	#7
liluoke Swabbie Join Date: Aug 2009 Posts: 10 Downloads: 8 Uploads: 0	i see, good points! i think going TOO slow will also be a waste of fuel, there has to be an optimum speed somewhere in between, i'll figure it out with the range button and let you guys know... lol i remember in das boot bad weather makes you burn a lot of fuel, should I go to periscope depth and try to ride out the storm like in the movie? =p

08-27-09, 02:16 PM	#8
gordonmull Lieutenant Join Date: Apr 2005 Location: Scotland Posts: 269 Downloads: 20 Uploads: 0	Save yourself the hassle! Here is a thread which should have what you're looking for. http://www.subsim.com/radioroom/show...ght=speed+fuel

08-27-09, 05:37 PM	#11
KeybdFlyer 中国水兵 Join Date: May 2006 Posts: 272 Downloads: 162 Uploads: 0	Get yourself a nice, flat calm day (0 mt/s). Select speed by actual knots, not "Standard, ⅔ etc). Try from (say) 6 kts to 10 kts and each time the speed has settled check with your NO "Max range at current speed". You'll soon find the optimum speed for maximum range for the type of boat you're in. ORrrrr... just d/l and install WB's Decks Awash mod that adjusts the setting for "Ahead ⅔" to give the best economy by default and sets the "Snorkel depth" command to give you decks awash by default (can be removed later when you get one fitted). I was in the process of doing exactly what WB had already done when I came across his mod - so in a fit of pique I checked all his settings in-game and guess what? He got 'em right, lol.

08-28-09, 07:22 AM	#12
Captain Nemo Ace of the Deep Join Date: Jan 2002 Location: London, England Posts: 1,144 Downloads: 54 Uploads: 0	Generally speaking I find 8 knots to give the best fuel efficiency. I am currently attacking a convoy heading for Halifax about 500 kilometres off the Canadian coast in my type VIIB and have still got over half a tank of fuel left. Might use the Belchen supply ship stationed on the Greenland coast on the way back though. Nemo __________________ "I'm afraid there is no disguising the fact that King's obsession with the Pacific and the Battle of Washington cost us dear in the Battle of the Atlantic". Sir John Slessor GCB, DSO, MC, DL AOC-in-C Coastal Command RAF ___________________________________________

08-28-09, 02:58 PM	#14
irish1958 Ocean Warrior Join Date: Apr 2005 Location: Carmel, Indiana Posts: 3,250 Downloads: 320 Uploads: 11	This was a concern in developing GWX. The ranges of the U-boats were tuned to be (on the average) the normal ranges for each boat at ahead standard. Sea state has a major effect on fuel economy. (and in real life, so does wind, ocean streams and circulation, quality of oil, state of the engine, etc.) Using the battery doesn't help, as recharging requires one engine to run to supply the energy to run the generator. I am not sure of this, but I suspect it would worsen markedly your range as pushing an U-boat against the resistance of sea water as opposed to air should increase the forces necessary to move the boat. __________________ Irish1958

09-23-09, 02:04 AM	#15
Snestorm Stowaway Posts: n/a Downloads: Uploads:	I just follow the uboat commanders handbook which states, the default patrol speed is Slow. Those other speeds are just for certain situations that may arise. It works. The most important thing you can do to keep your range high is NOT upgrade your diesels. The upgrade makes for unrealistic speeds anyway. Try it any way you like. My IXB always makes it back from Capetown, without refueling. Unless I sunk. Don't like those Capetown patrols. IXCs and IXD2s are better suited to that area. Long long ride.