Have driven the Warrego Highway many times as well, and I have never come across Tyrconnel,
.
Fuel stops I would suggest:
Roma
Blackall
Longreach
Mount Isa
Barkly Wayside Inn (fuel in Camooweal is VERY pricey)
Three Ways
....and then after that I'm not that up to date with costs or anything.
Fuel stops I would avoid:
Chinchilla (more expensive than Roma, yet closer to Brisbane. Go figure)
Winton (expensive)
Cloncurry
Camooweal
But Tyrconnel,
, can you take a photo of the place when you find it for us?
edit: Just looked up Tyrconnel on Google Maps, just north of Mungallala. Geez even Mungallala is a place which if you blink, you'll miss it,
.
morno