I usually use mid-grade gas and occasionally I'll throw in a couple of gallons of premium with it.

 

I'd gladly pay the extra 20 cents for added protection against detonation.

 

Octane is a rating, or a characteristic of gasoline. You don't add octane. Octane Boosters, i'm not sure what the hell they are. But this is how the octane number is figured out. (remember that octane is just a resistance to knock)

..."The measurement of gasoline octane quality most often used is the Antiknock Index (AKI). It is an average of the two ways that octane can be measured; the research octane number (RON) and the motor octane number (MON). Both the RON and MON measure the same things but do it at different speeds, temperatures, and spark advances."..."The antiknock index is stated as (R+M)/2. This is the number required by law to be listed on the octane decal on the gasoline pump."...

"Higher Octane Requirements:

*Advanced ignition timeing
*High compression ratio
*High air density (due to barometric pressure or turbocharging)
*Low humidity (dry air)
*Engine under higher load or lugging
*High inlet air temperature
*Lean air/fuel mixture
*14.7:1 air/fuel mixture"

--taken from "Automotive Service" Prof. Tom Gilles

 

I'd run the highest octane I could get locally for any Turbo II as we all drive these cars fairly hard and 99% of us are modded.

I run 93 octane here on Long Island, I prefer Shell if I can find it. The only downside is the $40 it costs to fill the car!! Thankfully, my 2004 civic Si daily driver gets a mean 32mpg hwy because @ the FC is luck to get 15 the way I drive it

 

on a NA FC, i'd say run the lowest you can get your hands on. my understanding of gas is that the higher the octane, the slower it burns, and the more resistant it is to knocking, and it burns hotter. the lower the octane, it burns faster, and cooler. faster burning in a NA=a little more power. i did a research paper in high school about the rotary vs. piston engine and their histories, and i read somewhere that there was a guy that ran a SCAA SOLO II race and placed very high with an NA rotary running 82 octane. on any turbo car, no matter what, i'd run premium just as a safeguard. with every oil change with my DD ('92 ranger, 3.0 V6, 5-speed), i throw in a bottle of Lucas Fuel Injector Cleaner and Upper Cyliner Lube and a tank full of premium and run the hell out of my engine for that tank. i only get about 200 miles for a 19 gallon tank vs. 300 on regular, still running pretty hard, but it burns out all the carbon and cleans my injectors really well and gives me a few extra mpg for a couple thousand miles, so i can see how a tank full of premium every once in a while on a NA car can help with burning off carbon deposits, but like what was said earlier, with a NA rotary run the lowest possible octane, and for a turbo run premium just to be safe.

 

I run 91 octane at pressures of 15 PSI and above...

But I spray alcohol...

 

what gas stations do you know of that sell under 87 octane? i remember a sunoco in detroit that used to have 85 "economy". i put it in my 85 new yorker and it ran like 2 miles then died and wouldnt start lol. i would like to find a place close to me that had 85 for my fc though. the new yorker had a 318 and wouldnt realy run under 91

 

Alright, I understand that how you drive affects gas milage. But let's assume I'm driving a mostly stock TII and that I drive in a civil manner (minus weekend racing ^_^). What would gas mileage be like under those circumstances?

 

~20 mpg on average if you dont speed by more than 10 mph and dont drive hard.