Had a bit of an interesting experience with the '97 TF and fuel.

First got it, 1/4 tank of random fuel
Ran down to 1/8, then filled up with apco premium
Ran that down to 1/8 (460km) then filled half up with BP Ultimate - slightly sharper response but not too much
Down to 1/8, filled up with $30 of BP Ultimate, at $15 the bloody thing spat fuel back out at me, thought my fuel sender was stuffed at that point
Again, down to 1/8 and filled it up with fuel injector cleaner and VPower - Wow, car feels like a bullet now and I got ~200kms from 1/4 tank!

Really need to sit down and figure out what the hell is going on.