Well I had my dad drive my car since I was away at school and didnt want it to sit. Well he filled it up with 87. So when I got back I had 3/4 tank of 87 and I topped it off with 93. How harmful is this, the car just doesnt feel right, seems to idle a bit rough.

 

Well from the looks of your Sig its a turbo car, so higher octaine is ideal, just drive safe keep it out of boost and then fill her up with 91-93 whatever.

 

Yea. Not a turbo guy here, so I go out of my way to look for 87, but I wouldn't push a TII with 87 in the tank. They're technically able to run on it, but it sounds like yours is slightly modded.

Stay out of boost (or low boost) until you're almost empty, fill up with 93, and go like a bat. Not worth risking an engine over.

-=Russ=-

 

the idling is not from the low octane. i am guessing since u were away it sat around for awhile and it just needs to be driven and redlined a couple of times.

 

Hmmm- this seems contradictory to the other posts....

 

Dude. Read the ENTIRE post. THEN reply. Possibly removing head from **** cavities first.

When running a modded TII on 87 octane for a tank, the LAST thing you want to do is redline the engine (which would, generally, give a full boost situation). Will the engine theoretically take it? Probably. Is it a good idea? Absolutely not.

-=Russ=-

 

if it is a stock TII i would say 87 is ok, since it says so in the car manual

but seeing your signature.... 87 is a little scary for your case

i say just keep filling the tank with 93 for at least through 1 complete tank (that means fill up at every 3/4 tanks FULL so u fill up 4 times) then it should be ok ^_^

since last time i ran 89 in my tank and well, with BAC failing also it knocked like crazy, but it was ok before the BAC was dead.... better safe than sorry i guess

 

Think I'd throw a bottle of Octane Booster into the gas tank just for insurance.

 

Alright I guess Ill just keep driving it carefully until I get enough 93 in there

 

Sport Compact Car magazine just did a test on octane boosters. They concluded that they really work. They tested the NOS Racing formula and Pennzoil/Quaker State's The Outlaw. Both were tested on Shell 91 octane. The NOS raised the rating by 2.5 points and The Outlaw raised it by 1.2 points. SCC also tested the boosters to a 15 gallon tank.

I agree with 87cncnu, add an octane booster for insurance.

 

87 octane fine for no turbo, turboed then adjust boost to octane or octane to boost , 130 octane then 30 psi boost, and a lot of variables in timing. It gets complicated thr higher you want to go, but it gets to be more fun!

 

That might help, but when you add octane booster, most of the manufacturers reccomend to pour the booster in before filling the tank to get a good even mix.

-Justin

 

Look man...just peddle it around town, and get rid of that gas. You DON'T want to knock. On my once stock 87 TII I WOT all the time on 87, and the car went over 167K miles. In the end she died from a collision with a bridge abutment. I highly doubt your father put the pedal to the floor.

 

over the counter octain boosters are bull **** poor a gallon of toulene it there and you will be up to about 100

 

ROLFMAO

 

ACC car also tested the toulene mixture, which did raise the octane of the Shell 91, but they had to add 4 gallons of it.

 

But how much did it raise it? I heard toulene raises your octane a lot more than the stuff in stores.
-Also Karack runs 87 in his TurboII, which is modded, BUT he commutes in it so he isn't on the throttle too much.

 

sais you... i redline it at least 2 times a day.

 

;[ ok....I don't see how you haven't fucked something up yet then.

 

If you are concerned why don't you siphon(spelling?) the gas out into a few gas cans and mow some lawns... then fill up with the good stuff? You could even put it back in your dads car and have him fill yours up with the right stuff.

 

this happened a month and a half ago, i dunno why people are sti.l responding

 

SCC added 1.5 gallons to a 15 gallon mix. Octane rating increased .8 points. Not 8 points, 0.8 points.

When they added 3 gallons, thats a 20% mix. Rating increased 2 points.

With a 30% mix, thats 4.5 gallons, the rating increased by 3.4 points.

This is all from SCC July 2005.

Note: The price per octane point gained for each mix.

NOS racing formula-----$0.27
The Outlaw---------------$0.22
Toulene 10% Mix--------$0.31
Toulene 20% Mix--------$0.25
Toulene 30% Mix--------$0.22

Like they said, "Octane gains and costs are comparable between off-the-shelf boosters and our home-brew boosters. But the convenience of a little bottle of booster, compared to 4.5 gallsons of toulene is obvious. Which would you rather carry in your trunk?"

 

c'mon man, thats what i meant. common sense would tell u that u need to fill it up with 93 octane before turning high revs. i was just saying that his idle shouldnt be a big thing to worry about. theres no need to be an ***.