The fuel selector dials have 4 main fuel tanks apparently. These are color coded in the sim (see below).
 

 

What is the difference between the 'Main tanks' labeled blue and yellow in the dials?

I read somewhere that the main tanks are actually those on the wing tips. One main tank for each wingtip. Can you confirm?  If true, why are there 2 blue and 2 yellow on the fuel selector dials?

Also, why would the left main tank be duplicated on the right dial and conversely the right main tank duplicated on the left.

Thank you.

Edited September 11, 20205 yr by oneleg
Clarity.

5 hours ago, oneleg said:

One main tank for each wingtip. Can you confirm?

Yes, that is correct.

5 hours ago, oneleg said:

Also, why would the left main tank be duplicated on the right dial and conversely the right main tank duplicated on the left.

The right dial selects the fuel source for the right engine, and conversely, the left dial selects the source for the left engine.  If your right engine goes out, you can switch your fuel source for the remaining left engine from left to right, and then right to leftt alternately in order to maintain weight balance.

Edited September 12, 20205 yr by StewartH

 

@stewarth Nice explanation.  Thank you.

Starting from 'cold and dark' the fuel selector must point to the crossfeed tank (colored yellow on the placard) to start the engine. What is the explanation for that?  Is it because the crossfeed tanks are located closest to the engine?

Edited September 12, 20205 yr by oneleg
Typo correction

Sorry if I answer for StewartH but I guess it's for checking that crossfeed is working properly.

13 hours ago, oneleg said:

Is it because the crossfeed tanks are located closest to the engine?

Well, there aren't any crossfeed tanks per se.  If you select "crossfeed", it means the left tank will feed the right engine and the right tank will feed the left engine.  Yeah, I know--it seems redundant.  But that's my understanding.  I personally have never used that setting.  In cruise, I use the aux tanks until there is about 10 gallons left each side, then switch to mains.

Stew

Edit to add:  In fact there is no crossfeed "setting".  Just to clear that up.

Edited September 12, 20205 yr by StewartH

59 minutes ago, StewartH said:

In cruise, I use the aux tanks until there is about 10 gallons left each side, then switch to mains.

In one of his many youtube videos, "31pilot" did a segment on prescribed fuel use from Main and Aux tanks during longer flights. Cannot fine it right now.  Had it bookmarked before my previous computer system failed. If I recall accurately he burns from the main tanks for 90 minutes, switches to Aux tanks and burns from them until entering an approach pattern, then switches back to the mains.

Here is a link to the 310 POH.  A description of fuel tank use during cruise is on page 1-10.

https://usaeroflight.net/wp-content/uploads/2016/12/Cessna-310Q-PDF.pdf

@fppilot  Here's the video from 310pilot you were referring to.  I'm not at all sure the Milviz 310R fuel system works in the manner he describes.  In fact, I doubt it.  But here you go.  Start at 11:30 into the clip:

https://www.youtube.com/watch?v=cJwteTldPu8

Stew

 

As this was designed in conjunction with a real pilot/owner of a C310R.... we're going with how it works now.  Thanks.

17 minutes ago, Milviz said:

we're going with how it works now

Out of curiosity, can you elaborate?  Don't get me wrong--I have no problem with how the fuel management seems to work already, but I don't think it works quite the same as Kevin (310pilot) describes his system.

Thanks for posting the link for the video by the C 310 pilot. I guess my question would be, "Is there a flightsim limitation (FSX, FSX Steam & P3D) regarding a\c fuel management that would not allow full fuel management as described by the C 310 pilot? Maybe the "Crossfeed" function cannot be modelled due to flightsim limitations??? Only a guess on my part.

@StewartH

15 hours ago, StewartH said:

Well, there aren't any crossfeed tanks per se.  If you select "crossfeed", it means the left tank will feed the right engine and the right tank will feed the left engine.  Yeah, I know--it seems redundant.  But that's my understanding.  I personally have never used that setting.  In cruise, I use the aux tanks until there is about 10 gallons left each side, then switch to mains.

Stew

Edit to add:  In fact there is no crossfeed "setting".  Just to clear that up.

 

@Stewarth  From the manual, see item 'd' below. Now I don't know what the label 'Crossfeed' below is for then... does anyone know?

14 hours ago, fppilot said:

In one of his many youtube videos, "31pilot" did a segment on prescribed fuel use from Main and Aux tanks during longer flights. Cannot fine it right now.  Had it bookmarked before my previous computer system failed. If I recall accurately he burns from the main tanks for 90 minutes, switches to Aux tanks and burns from them until entering an approach pattern, then switches back to the mains.

Here is a link to the 310 POH.  A description of fuel tank use during cruise is on page 1-10.

https://usaeroflight.net/wp-content/uploads/2016/12/Cessna-310Q-PDF.pdf

@fppilot. This is very helpful. Thank you.

Support forums for questions (and answers)

 

4 hours ago, oneleg said:

@fppilot. This is very helpful. Thank you.

If you poke around with web searches for Cessna 310 and fuel tanks you will find some interesting information.  One article, I believe at AOPA, profiles that the workings of the fuel systems in the 310 went through iterations over the years.  The main, or tip tanks were present at first.  Aux tanks were soon added in the wings.  Then iterations in flow management developed from model update to model update.  The Milviz 310 and 310R if I recall are very closely modeled to one specific owner's 310.  One specific airplane.  That as opposed to modeling to one general version of the 310.

I fly the 310 regularly.  My flights average just under two hours, but have been as long as four hours.  I start and stay on main tanks until they are half drained.  Then I switch the Aux tanks until they reach about 20% remaining, or when entering an approach pattern, whichever comes first. On longer flights I run Aux down to perhaps 10%, setting a timer to warn me.  Then I switch back to the main tanks.  I do not routinely use crossfeed so have no idea what the behavior is there.

@oneleg  Your original illustration in post #1 shows the fuel levers in a "crossfeed" configuration.  The left-hand switch is feeding the left main tank to the right engine, while the right-hand switch is feeding the right main tank to the left engine.  That is the definition of "crossfeed".  Notice the solid "yellow" border of the dial setting in each case.