I've been wondering this for a while,
The manual for the TW says it has a 71 litre tank, I've been wondering how much of that is actually usable?
The lowest I've been is '60 litres used' on the trip computer and the guage is slight under empty.. so naturally thinking i'm seconds away from fuel starvation I fill up.
Obviously there is room for expansion but how much of the 71 litre tank can be used?

All of it, the reason it becomes empty at 60L used is because it uses the next 10L as a reserve, AFAIK.

Yep, what Matt said.

My wife's car has a 40L tank, I think the most I've ever put into it is 35L and that's after running around with a low fuel light for over 60km.
My Magna is a bit thirstier, so I try not to push the light very far.

When you had an indicated 60L used, how much did it take to fill up? I've had my Magna for almost 2 years and still haven't learned to trust the computer :)

I trust my litres used more than the guage lol
I've gone to 65ltrs and filled up with 66, so it is accurate.

I find the 'fuel used' to be spot on (+ - 1 litre)
ok, I guess the test is to fill up the jerry can and aim for 65+ litres.
Will be interesting to see what it gets to before it runs out.

The way I used to do it with the old commodore was to wait until I heard the fuel pump cavitating.

Trouble with running close to empty means you can overheat the fuel pump as it sits submerged in fuel which cools and lubricates the pump.
The old Commodore fuel pump sat in a swirl pot and return fuel cooled the pump as well.

I've found mine to be accurate to within a litre i.e use up 55l and the bowser stops at 54.5 - 55.5

Same here - I dont watch the fuel guage - I go by the L Used function of the trip computer, I reset it every time I fill up (along with averages etc)

Its accurate to within 1L +/- so its quite reasonable.

I have been able to put 65L back into my tank - when the TC was saying ~66L used.

As above - dont run your fuel tank low - as it cools the pump etc.
Also - running the tank low, will increase changes of picking up the crap that is on the bottom of the tank that unfort gets pumped in with the petrol occasionally when filling up.

I usually just wait until the fuel light comes on, then know i have to fill up sometime in the next roughly 40kms to be safe.

I usually fill up or put in $20-30 whenever petrols cheap.

I run my 02 VR-X on 91 Ethanol, constantly gets 10.8 l/100 as per the trip computer. If I run it on 95 or 98 it gets about 12.5l/100. Strangely I drive it the same but get less out of the tank.

I usually fill up or put in $20-30 whenever petrols cheap.

When petrols cheap? Is that when pigs fly?

I've been able to get 60kms without running out after to needle hits empty. I try not to do it too often, cause thats 60kms of fear! haha

In my TW VRX AWD, which has a rated fuel capacity of 70 litres (ie 2 litre less than the 2WD sedans - which are rated at 72 litres), the low fuel light switches on when I've used about 52 litres. Yesterday, I put 69.74 litres in it. Around town I typically find the amount of fuel used is around 2-3% more than indicated by the fuel meter (eg when it says it's used 67 litres it's actually used 68.5-69). On a long trip, it's almost spot on.

INteresting thing i noted. To fuel light in my VRX i got to use 56L of fuel. In my Ralliart it gets to about 61L used before fuel light. This will not give you any usefull information but i just thought i would say what i found out. :) Could be due to the Ralliart having a different shape fuel tank. Either that or the vr-x was retarded.