93 Octane vs 91 Octane
 

I read in the owners manual that the fr-s requires 93 octane gas. In the States the best we have is 91 octane. How much does that effect the performance of the car and does it damage the engine in anyway?

In YOUR state lol. 93 is readily available where I live. E85 too

I'm pretty sure 93oct is available in most places outside Cali. 91oct won't damage anything although this is lowest octane you should run in a 12.5:1 compression engine like the FA20. The ECU will adapt to 91oct but will obviously not perform as well.

Firstly, other states do have 93 octane. Perhaps not at all gas stations but I have no trouble finding 93 in NY.

Secondly, the difference between 91 and 93 is very small. Using 91 will not cause any problems unless you have an incredibly aggressive custom 93 tune. Theoretically there is a performance difference but you'd need a dyno to really tell. I doubt most people could accurately tell which is faster in a blind test.

If 93 was really necessary over 91 the car wouldn't be sold in California.

Or in parts of Canada. I've never seen 93 in New Brunswick or Nova Scotia.

I'm sure the owner's manual says something like, "Use 93 octane if available, otherwise 91 octane* is perfectly acceptible."

93 is recommended. 91 is minimum. The engine runs safely on 87 as I understand it, just not well.

Elevation affects octane requirements. 91 is the most common up here in Calgary at 1,000 meters elevation (3400 ft). I've used 94 with no noticeable effect, probably because the thinner air up here can't use more octane.

If you are in coastal areas you should be able to get 93 or 94 easily.

Yea I grabbed a tank of the petro 94 when I was down in the city. Didn't really notice anything from the usual 91 shell.

Petro 94 is simply 91 with 10% ethanol.

sorry confused myself, not petro 94, ultra 94 octane at petro.

and if thats still the one your thinking about, link to info?

I can't give you a link right now, but a quick Google search should give you some results. It's even written on the pumps when you go at the station IIRC

Sent from my SGH-T999 using Tapatalk

He's correct. I put 94 from Petro in, and my crickets started instantly.

Yea he said the octane is still 91 though? I know it's got ethonal but it doesn't bother me.

Technically, it is 94. BUT not 94 pure gas. It's a blend with ethanol in it. =)

Sent from my SGH-T999 using Tapatalk

I see some turbo numbers on 93 up as high as 330whp.

If I have WMI on 91, would that be equivalent to 93 at least?

I bought the WMI along with the FB turbo kit system hoping to get some better numbers than just 91 could offer.