Some of you regulars and those who know me personally are aware that I happen to drive a global specced (one that the official Subaru dealer brings in instead of those grey market imports) Subaru Impreza 1.6ts and the good thing about this car is that it has 80% of the performance of the Impreza WRX and the fuel consumption of a regular 1.6liter car (mine anyway).
Now the other fun thing about running a global spec Subaru is that it runs happily on RON92, 95, 97, 98 or even 100. This is unlike the JDM (Japanese Domestic Market) cars that are actually very very happy with 100RON. You put our 97 and it basically runs happy albeit with slightly less power due to the ECU retarding ignition timing a fair bit. Then you try RON95 because RON97 costs a whole lot more these days. Now non-turbo cars wouldn't have much problems as things aren't tuned so aggressively but when you have a turboed Impreza or even a Lancer Evolution, the car's ECU would already be working overtime trying to keep the engine from running lean and then prematurely detonating thereby requiring an expensive overhaul.
And when you start modding the darn thing it gets trickier. Add an exhaust system, intake and up the boost things go wonky and the stock ECU that is already compensating for lower octane will give up and head for home if you try running RON95. If you still cannot get it, it basically means that the engine bites the dust, kicks the bucket, heads for the happy hunting grounds, swims with the fishes or gets killed to death if there ever was such a term. So how do you go about doing up a Subaru Impreza WRX or a Mitsubishi Evolution properly? You go for a proper tune-up job.
