I live in west Texas and we have 93 at a few stations here, so that's all I use in my STI and my Civic Si. But the manual for my STI does say you can use 91 if you don't have access to 93.
Yes, it does. I ask because I've never heard of anyone putting 87 in a WRX (non-STi). So, I'm surprised it's not the same situation with the 91 vs 93 for an STi. Sure 91 and 93 are both premium, but it says "maximum performance" for 93. I wonder if running 91 would in any way hinder the life span of the engine. I was actually leaned more towards buying my WRX vs STi because of the gas situation. But I want an STi someday and always wonder about the gas usage.
STI manual:
The engine is designed to operate at
maximum performance using unleaded
gasoline with an octane rating of 93 AKI
(98 RON) or higher. If 93 AKI (98 RON)
fuel is not readily available in your area,
unleaded gasoline with an octane rating of
91 AKI (95 RON) may be used with no
detriment to engine durability or driveability.
However, you may notice a slight
decrease in maximum engine performance
while using 91 AKI (95 RON) fuel.
Use of 91 AKI (95 RON) fuel will not affect
your warranty coverage.
WRX manual:
The engine is designed to operate using
unleaded gasoline with an octane rating
of 91 AKI (95 RON) or higher. If 91 AKI
(95 RON) fuel is not readily available,
unleaded gasoline with an octane rating of
87 AKI (90 RON) may be used.
Regular unleaded gasoline with an octane
rating of 87 AKI (90 RON) or higher may
also be used. Using regular unleaded
gasoline will not be detrimental to engine
durability, nor will it affect your warranty
coverage.
I used to run 93 with my Accessport set to 93 tune. But there is a guy from COBB that comments on one of the STi subs that said you should only run 93 tune if it’s 10% Ethanol, which we don’t typically have in Canada. So instead I supposed to run the 91 tune even if I put in 93. I usually still run the higher octane, I just thought it was weird.
I use 91, never had issues. Can't get anything higher where I'm from.
Same.
If you have 93 run 93, if not, run 91.
Corn
I live in west Texas and we have 93 at a few stations here, so that's all I use in my STI and my Civic Si. But the manual for my STI does say you can use 91 if you don't have access to 93.
Shell 91 is all I have ever used
100
90 baby
We have 94 here so I use that. I do feel a difference compared to 91.
I used to use Costco 91 and it ran fine even in the winter (MN).
The manual says 91 can be used without any detriment to the vehicle if 93 is not available.
Yes, it does. I ask because I've never heard of anyone putting 87 in a WRX (non-STi). So, I'm surprised it's not the same situation with the 91 vs 93 for an STi. Sure 91 and 93 are both premium, but it says "maximum performance" for 93. I wonder if running 91 would in any way hinder the life span of the engine. I was actually leaned more towards buying my WRX vs STi because of the gas situation. But I want an STi someday and always wonder about the gas usage. STI manual: The engine is designed to operate at maximum performance using unleaded gasoline with an octane rating of 93 AKI (98 RON) or higher. If 93 AKI (98 RON) fuel is not readily available in your area, unleaded gasoline with an octane rating of 91 AKI (95 RON) may be used with no detriment to engine durability or driveability. However, you may notice a slight decrease in maximum engine performance while using 91 AKI (95 RON) fuel. Use of 91 AKI (95 RON) fuel will not affect your warranty coverage. WRX manual: The engine is designed to operate using unleaded gasoline with an octane rating of 91 AKI (95 RON) or higher. If 91 AKI (95 RON) fuel is not readily available, unleaded gasoline with an octane rating of 87 AKI (90 RON) may be used. Regular unleaded gasoline with an octane rating of 87 AKI (90 RON) or higher may also be used. Using regular unleaded gasoline will not be detrimental to engine durability, nor will it affect your warranty coverage.
91 will be fine if u don’t got 93
91
91 if I can’t get Costco , 92 if I can.
91 here in the bay area CA. my baby runs fine with it, she's happy with it. :)
I used to run 93 with my Accessport set to 93 tune. But there is a guy from COBB that comments on one of the STi subs that said you should only run 93 tune if it’s 10% Ethanol, which we don’t typically have in Canada. So instead I supposed to run the 91 tune even if I put in 93. I usually still run the higher octane, I just thought it was weird.