This makes most sense. Any cars that has been tuned to run on either Ron 95/97, be it modded tune or factory setting, pumping Ron 100 without a retune would yield very little benefit, or none at all. Smoother perhaps, but the power gain will not be noticeable by your butt dyno. Many are psychologically convinced though

My STI which came factory tuned to run on Ron 98, has been retuned to run smoother on Ron 97 (thanks to AE Subaru). I do wish to tune it to Ron 100, but only if more and more stations have them. No point retuning, then can't find it when I need it. End up, engine being retarded all the time pumping Ron 97 with Ron 100 tuning.

FD2R came CBU with recommendation to run RON 100, sold by Honda Malaysia. However, it will still run on RON 97, though with slight retardation. When custom tuning was done with mods, the tuning was also done with RON 97 since that was the highest available. My current 2015 STI, sold by Auth Dealer Motor Image, came recommended to run on RON 98. Now retuned to run on RON 97 for more efficiency.

Most cars can still run on RON 97, even if the recommendation is higher. The only setback is, the car generates lesser power at certain range. However, cars that came factory tuned to run lower RON, pumping higher RON rating does not necessarily equate to more power. This is something people still fail to understand.

Thus, it is not that it DOES not need. It is preferred if factory tune came with it. No one buys a performance car, only to pump lower RON octane to generate lesser power by saving petrol money. If want to save petrol money, don't buy performance cars that came recommended with Ron 97 and above. I laugh when I read an FD2R owner wanted to tune his car to run on RON 95. Get a normal FD if that's the case ...

Most VW are not performance cars, hence they came factory tuned to run on RON 95, to appeal to a bigger pool of potential buyers. You may then rechip/remap to run on RON 97, and it will net more power. Just don't drop back to RON 95 with RON 97 map.

I cannot say the same for GTI/GTI-R since I do not know what it was recommended to run on. I would like to know.

My STI fuel lid.


Pumping RON 100 for the first time, with about RM15 worth of RON 97 still inside.Haven't really travelled much with it, less than 50km. Doubt I'd feel any difference since it's been retuned with RON 97 2 months ago. Just itchy backside must try ..

Or Apple shouldn't make iPhones .... and whole bunch more.

It's ok .. we need our dose of laughter from time to time.

You are right. Compatible? yes. Necessary? No.

I believe it meant to use at least RON 95. Anything lower just increase the risk of engine knocking.

As for myself, it's been erratic on my power band. I'm waiting to finish up the current fill, and refill one more time for a more consistent effect. Need more mileage on it for a more accurate review. Weekend car doesn't help with mileage ..