excellent. Im going to go get a tank of this stuff when I get my car started. 

Tried it, made a difference but not enough to care. It's not so easy to find now either, some servos have it for a few weeks then nothing for months. That was with my 300+rwkw 98 tune. In the words of Hitman "if your tune can't handle that little ethanol, you've got other problems too". Wouldn't hesitate to use it with a stock ecu, given they're so rich in the first place. From memory, you'll run approx 0.2:1 leaner with United 100.

Ok so I've been using this fuel on my gen2 turbo (CT26 and stock ECU) for a few weeks now. Current power mods full 3" exhaust turbo back, 'ebay intercooler', pod filter, ATS racing TB inlet, ATS racing MBC set at ~12 psi.
 
Some of my observations so far compared to straight ULP98, I assume this is down to it running at full JDM 100 octane capability + oxygenating effect of 10%E:

• Overall smoother/more responsive off boost driveability 
• Quicker turbo spool
• Noticeably better over 4000 rpm at WOT 
• Also seem to be getting noticeably better fuel economy for some reason (bonus!)

This just shows how bad our ULP98 really is running stock JDM ECUs - feels like the car is much more 'alive' now! love it.
 
 

Back a few years ago when I was at the most competitive stage of my go kart racing, my old man, who is an industrial chemist, took samples from all the different providers in town (including the 100 ron stuff from united) over the course of a month and tested them all with a gas absorption spectrometer, the results were that the bp 98 was better by a good margin. I cant remember the specifics, but the components of the bp lent itself to a better torque curve across the range. We tested these results with back to back runs on an engine dyno and were validated.

Engineering_guy

Back a few years ago when I was at the most competitive stage of my go kart racing, my old man, who is an industrial chemist, took samples from all the different providers in town (including the 100 ron stuff from united) over the course of a month and tested them all with a gas absorption spectrometer, the results were that the bp 98 was better by a good margin. I cant remember the specifics, but the components of the bp lent itself to a better torque curve across the range. We tested these results with back to back runs on an engine dyno and were validated.

 
I agree with this - a mate of mine who is a Chemical engineer who also has a love of cars, did similar tests with the BP Ultimate (98), United 100, V Power, Caltex Vortex 98 and a regular unleaded BP 91, and found that the fuel that outperformed the others was BP Ultimate.  On the dyno it had a greater torque curve in the midrange to top while also having a low EGT.  
(Funnily enough, BP 91 (regular unleaded) had the lowest fuel consumption, even out performing the higher octane fuels with fuel consumption.)
 
BP Ultimate all the way - I was using it in my CBR250RR before I had the MR2 and have been using it in the 2 ever since I've had it.  Remember, these cars with 3SGTE's were tuned (ECU and timing) in Japan where they have much higher octane fuel (100 RON) as regular fuel compared to here.