Well I have a sc4, but if I were to put 87, the knock sensor would detect the slight knock and compensate in timing. The ecu would retard timing and thus making the engine run hotter, but I don't think it's enough to overheat.

I have also made the same mistake of putting in 87, but the car seemed fine to me, sure I didn't get on it, but I was still getting 20 mpg.

 

i had 87 in my car and if i would accelerate even moderately fast then it would sputter and knock and miss out. i put in premium and it ran fine.

 

In my opinion, you are better off putting in the good stuff and keeping your foot out of it if you are worried about gas prices. If you can't afford to feed it right, trade it in on some 4-banger crap bucket.

 

arent Evo's, STI's, and s2000 all 4 bangers? i dont think they are "crap buckets"

 

I think he meant "crap buckets" that can take 87 octane/good on gas.

 

This might sound a little crazy but why don't you but a civic or a car that is actually FUEL EFFICIENT. 100 miles per day is a lot of driving and an SC is far from efficient.

 

I even tried to run regular premium (as opposed to hi-octane premium) and my car drove like ***** afterwards. Anything that is 98RON~ is the only fuel I'll put in there.

BTW I've noticed that Shell has a new fuel that's out now (V-Power Racing) and it has a 5% ethanol blend. How would this effect a factory turbo car?

 

I use 91 octane on all my cars but today i put race gas in my RSPSC, like 9-10gal for $65 but i will enjoy every drop of it when i hit the gas pedal

 

I was in Hawaii and a mechanic was telling me he feels he is doing more engine repairs since ethanol was introduced to the islands, he added that he has replaced more engines in the past few years then ever before.
Anyone else know about Ethanol?

 

all gas in the states is 10 percent ethanol. It wouldn't affect performance noticable at all.

your 98 grade and the American premium are one and the same, the rating systems are different.

I use nothing but 93 octane, cause god knows what the previos owner used, and how it gummed up the fuel tank and filter.

 

id buy a civic but then id be driving a civic, lol. I want something luxurious that is comfortable with heated seats, etc that is good on gas. 20mpg isnt bad but there seems to be no reason to put in premium when im driving 100 miles a day and never beating on it what-so-ever, just cruising at about 80 the whole time.

 

100 miles a day ~ 5 gallons. Extra $0.30 a gallon is $1.50 per day. Lets say its 250 days a year to get you 25000 miles. Are you serious ! $375 for the year. Get over it or get rid of it.

 

that is a no no i would never put 87 in my car i only put 91... its not worth messing up the car just over a few bucks it even calls for premium at the gas cap....if gas price is a problem get something more better gas mileage...

 

Buy a more fuel efficient car.

 

I will pay a $375/yr luxury tax to drive a luxury car.

High compression luxury/performance motors need the high octane fuel to produce a clean enough combustion to not cause knock or anything worse.

If you want to use regular 85 octane, get a 2.5mm HKS head gasket for $375 and then enjoy your 180hp 3L all year long.