adhar wrote:cadud2000 wrote:does that mean you could get the same octane results if you use premium 98 Octane and then add an octane booster into the fuel. would that increase the power much?
does octane booster fuel additive actually make a noticeable difference?
It would need an ECU remap to get the real benefit of running higher octane fuel
When the v5 STi WRX was released in Oz in 1999 it had JDM tuned ECU's and at that time the 'premium' here was only 95 octane, so many engines blew up and were rebuilt by Subaru. A remap of all the ecu's brought the japanese power of 206kw (some cars were more) down to 195kw.
Octane booster is more for protection to ensure that 'pinging' doesn't occur. If you put octane booster in a standard car it won't really be a noticeable difference but if you are ever suspect of fuel quality or can only get 95 (and need 98) it can be a good option.
My car has had an ECU tune, and whenever i track it i put octane booster in it just for protection when driving hard, but i wouldn't expect more power.
The JDM stock tune is identical to the "Tuned by STi" ECU tune; I studied this quite a bit before pushing the STi tune to my stock '05 LGT. I was concerned the JDM tune would not run happy on our crappier fuel (Since both LGT and tuned by STi Liberty runs on 98RON minimum I was convinced), after a few months of this tune the car is just as happy and gives you what Subaru charges $1500 for; the STi ECU upgrade.
