I have a Manual 3lt TD Surf & average about 12.5l/100.When we fillup we will
at most be able to put 50-55lt in, & we get about 450-480K out of that.

Maybe its the Manual, Maybe its the 3lt.  Neither my wife nor I are light
footed, when we were it used to go through more.  Something I have found
however is fuel quality makes about 100k difference.  Safeway fuel it will
go through 55lt in about 350k.

D

Haven't got a tank for sale, but I might be able to save you a lot of money.

If you are prepared to lose your undercar spare tyre carrier (not a problem
on a Surf as they already have either a rear hatch mount, or the captive
bolts to mount one) it is a relatively trivial job to mount a Nissan GQ
Patrol fuel tank between the rails where the tyre mount was (at last
something useful from a Nissan). These can be had for as little as $50 from
wreckers.

Next you need the filler neck with manual dual tank changeover valve from a
late 80s on Troop Carrier. This is somewhat smaller than the similar device
fitted to Landcruisers, the Troopie part will fit inside the panels of a
Hilux in place of the standard filler, the Landcruiser part will not. Some
bending, filing, grinding and filling is required however, for one thing the
mounting holes in the fuel filler alcove do not line up.

The solenoid changeover valves and fuel gauge change over relay from either
Troopie or Cruiser is also required. Try to get the wrecker to let you do
the removing, that way you can preserve most if not all of the fuel line and
hoses (and get an idea of how it all goes together).

For under $300 and the investment of a weekend you are up and running with
more than double your original fuel capacity.

Notes.
If you have not already done it, you will be putting new rear springs into
the Hilux, fortunately, for the coil spring models this is a 30 minute job..

In regards to adding additional fuel tanks and interfering with your
vehicle's fuel systems, doing this yourself may breach a veritable raft of
regulations, rules, etc. It will also almost certainly void insurance
contracts, roadworthy etc. Disposing of whatever was in the GQ tank when you
bought it will also put you in breach of the EPA legislation into the
bargain.

Keep it looking workman like and steadfastly maintain  that it was like that
when you bought the vehicle and you thought they were all like that so you
didn't realise that it was modified will get you around your insurance
company, the public servants couldn't care less unless you either dump 80
litres of fuel on the road outside a primary school, old people's home or
the PM's  residence  or (God forbid) emulate a Buddhist monk and incinerate
it.

The last is good as most (if not all) the evidence is destroyed, unless some
incredibly vapid Caravaner comes to a screeching halt across three lanes of
traffic and breaks out the Aviation Fire and Rescue sized extinguisher and
puts it out just after it is too f.cked to be repaired but with sufficient
evidence still existing to excite both insurance companies and public
servants (don't laugh happened to a mate of mine who was standing by not
actually happy about his heavily modded troopie burning to the waterline,
but sanguine with the prospect of using the insurance money he didn't get to
build a new one. Had to pay for repairs to the road too).

Tony Smith