89 Octane Gas in a 96 Turbo

[v0od0o]

I know it might sound crazy, but gas prices in California is crazy, it is $3.33 just today (8/31/05) and it is still raising.

I don't know if it has been done before, I'd done searches and FAQ's, no information, so here goes...

What if we keep our wastegate open at all time? then is it possible to run 87 octane since no boost is created?

If the answer is yes above, how can I modify my wastegate actuator or wastegate actuator arm or wastegate flap to open?

Thanks for listening guys, criticism accepted .

 

[kronix0420]

i dont even spend the money on premium, i only run 87 grade fuel and i have never had a problem

 

[Dark_Horse]

You will be just fine. Figure worst case scenario is you're at 91 octane now. Everyone in CA runs turbo cars on 91 and is just fine.

 

[mr95gst]

It will be fine just don't get into real high boost numbers or you will get a little knocking. Not very likely should still equal out to around 91.

 

[Sotarts]

I'm just curious how detrimental a few gallons (About 4) of 89 octane gas going in a 96 TSi AWD would be to the car's health? I let my dad borrow my car and he put some in. I would say there was an equal amount of 93 in the tank before that. I understand that mixing different octanes averages out sort of. So, should I maybe lay off the boost a little until I drain the tank and refill it with 93 octane, or you think it will be okay averaging out to about 91 octane?

I would add some octane booster from auto parts store (first), then top it off with 93 (or higher if you can find) and turn down the boost. Drive milder until you use up the fuel in the tank. You can always log your car to see if anything bad is going on.

I'd rather be patient and ride it out easy, than learn the hard way and spend few grand later on--shit happens. Patience pays off and prevents shit from happening.

i dont even spend the money on premium, i only run 87 grade fuel and i have never had a problem

Good luck with 300-350 hp daily driver wish, you'll blow up your engine before you know it. That's just sad.

 

[CanadianTSi]

You will be fine, if anything just don't push it too hard until the gas is gone.

 

[CowPimp]

I would add some octane booster from auto parts store (first), then top it off with 93 (or higher if you can find) and turn down the boost. Drive milder until you use up the fuel in the tank. You can always log your car to see if anything bad is going on.

Ah, good idea with the octane booster. I'll probably drop some in this weekend and then top it off with 93 octane. Good call.

I appreciate all of your responses. I know I'm being paranoid. The only reason I even asked was because I run 17PSI with stock injectors (Upgraded fuel pump though) which is kind of pushing it. I'll just take it easy on her for a bit. Thanks again.

 

[Defiant]

I let my dad borrow my car and he put some in.

Dads. Show him the damned UNLEADED PREMIUM FUEL ONLY on the gas gauge and on the goddamned filler door, and ask what shit you'd be in for doing that to something of his.

I would say there was an equal amount of 93 in the tank before that. I understand that mixing different octanes averages out sort of.

Actually, it can slightly boost the rating.

So, should I maybe lay off the boost a little until I drain the tank and refill it with 93 octane, or you think it will be okay averaging out to about 91 octane?

You'll be fine. But he owes you.

 

[leftovercrack]

i dont see the point in running anything less than premium in your turbo car. you save a couple hundred bucks over the year for a car that wont be as smooth as a car with a few cents "more expensive" fuel. my dad filled up my 2000 celica gt-s wiht 87 and it drove so back went an overwhelming desire to cut my wrists for what happened to my car. .

 

[dave99gst]

even the manual says you dont have to run higher octane fuel. I believe it says
somthing like " there may be a notable performance loss "

 

[kronix0420]

I would add some octane booster from auto parts store (first), then top it off with 93 (or higher if you can find) and turn down the boost. Drive milder until you use up the fuel in the tank. You can always log your car to see if anything bad is going on.

I'd rather be patient and ride it out easy, than learn the hard way and spend few grand later on--shit happens. Patience pays off and prevents shit from happening.



Good luck with 300-350 hp daily driver wish, you'll blow up your engine before you know it. That's just sad.

i know you say i'll blow my car up, i know i do run 87 octane fuel, but i do use two diff additives, i use AMSOIL performance improver injecter cleaner, its also guarenteed to increase octane by 2 points, and i also use AMSOIL octane boost, guarenteed to increase octane by 7 points, i failed to put this in my post, sorry so i guess in the end i'm at about 96 ocatane on average, my dad is an AMSOIL dealer and i get the additives for free, so thats why i dont fork out the cash for premium grade fuel

 

[Sotarts]

i know you say i'll blow my car up, i know i do run 87 octane fuel, but i do use two diff additives, i use AMSOIL performance improver injecter cleaner, its also guarenteed to increase octane by 2 points, and i also use AMSOIL octane boost, guarenteed to increase octane by 7 points, i failed to put this in my post, sorry so i guess in the end i'm at about 96 ocatane on average, my dad is an AMSOIL dealer and i get the additives for free, so thats why i dont fork out the cash for premium grade fuel

If you buy name grand gasoline on a regular basis, you do not need to use any goofy additives. The government requires detergents/additives to be part of gasoline, espeically higher grade gasoline. To use additives is simply a waste of money and your catalytic converter may suffer over time and who knows how all the seals reaact to all the additives you're using. Additives are bullsh*t. Additives are a temporary solution (like when you accidentally fill up with 87, a vehicle that REQUIRES PREMIUM UNLEADED FUEL O N L Y), not a permananet BY ANY MEANS.

But I guess you know better than Mitsubishi engineers. Furthermore, if you're runing not much more boost, your 96 octane "rated" gasoline partially becomes waste, because engine is not burning all of it and it's simply being spewed out into atmosphere, pulluting our air and clogging catalytic converters. Runing rich is not great for performance either.

 

[TJGoSurf]

If you buy name grand gasoline on a regular basis, you do not need to use any goofy additives. The government requires detergents/additives to be part of gasoline, espeically higher grade gasoline. To use additives is simply a waste of money and your catalytic converter may suffer over time and who knows how all the seals reaact to all the additives you're using. Additives are bullsh*t. Additives are a temporary solution (like when you accidentally fill up with 87, a vehicle that REQUIRES PREMIUM UNLEADED FUEL O N L Y), not a permananet BY ANY MEANS.

But I guess you know better than Mitsubishi engineers. Furthermore, if you're runing not much more boost, your 96 octane "rated" gasoline partially becomes waste, because engine is not burning all of it and it's simply being spewed out into atmosphere, pulluting our air and clogging catalytic converters. Runing rich is not great for performance either.

Unless you're a mistubishi engineer you have no right to speak from their point of view. Now don't attack Amsoil, they are probably the best oil company in the world and they dont make additives for bullshit. Perfect example, you arent supposed to run synthetic in rotaries you goto their website and look up recommendations for oil for an RX-7 it will say, "Not recommended for use". Hard to believe a company may be here just to actually do what it promises.

 

[Morphius]

I don't really see the big deal with 89. I've ran 89 since the day I got my (now retired) 90 GSX. I logged 60K+ miles on it. Stock turbo, boost set at 15 psi, 3 inch turboback. Never had an issue. The car is only parked now because I have to many cars where I live and needed a vehicle when I fly home on the holidays. It still runs awesome with 200K+ miles.

Now granted, I never logged it to see what it was doing. It may have been knocking and pulling timing. My bad for not doing it, no excuses there. But again, I put 60K+ miles on it that way and it still runs great.

If your car is modded, and running higher boost, then it might be a good idea to run higher octance. If your're worried about it, log some data and see what it's doing. Likely you're fine.

 

[Denji]

I would add some octane booster from auto parts store .

I would put in 91 or 93 octane instead, much more effective of an octane booster

Ah, good idea with the octane booster. I'll probably drop some in this weekend and then top it off with 93 octane. Good call.

bad call, octane boosters are practically worthless

i know you say i'll blow my car up, i know i do run 87 octane fuel, but i do use two diff additives, i use AMSOIL performance improver injecter cleaner, its also guarenteed to increase octane by 2 points, and i also use AMSOIL octane boost, guarenteed to increase octane by 7 points, i failed to put this in my post, sorry so i guess in the end i'm at about 96 ocatane on average, my dad is an AMSOIL dealer and i get the additives for free, so thats why i dont fork out the cash for premium grade fuel.

I would be one of the guys saying your going to ruin your car, becuase you misunderstand octane points and ratings.

if you put 87 octane gas in your car and add your octane boosters, what you dont know is that there are 10 octane points to raise your gas octane 1 number. Your grand idea is to buy 87 octane and add 9 octane points. Congratulations you are running on 87.9 octane bud!

heres a link on how to make some real homemade octane booster that actually raises octane a more significant amount, and hey, they even poke fun at the little cans of "octane booster" you get at the store and their misleading clames.- www.elektro.com/~audi/audi/toluene.html

 

[Sotarts]

I would put in 91 or 93 octane instead, much more effective of an octane booster
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There's only so much gas you can top off the tank with before it's full. Replacing some of that gas (like adding a bottle) with octane booster will help. May not mean a whole lot, but the booster will do its intended job. Usually, the bottle treats up to 20 gallons and DSM's have smaller gas tanks.

Personally, I would find 100 octane gas instead. I know where there's a gas station selling it around me, so that would be my #1 solution.

I haven't seen anyone mention it, but the guy who has this issue and is asking for advice is runing "FP Big28@17psi". I bet no one took THAT into consideration, have you all? He NEEDS for the gas to be at least of premium rating. More so with more boost and higher airflows.

This topic has been beaten up to death.

The end.

 

[ilikespeeding]

I was wondering something...sorry to thread jack but we are on the subject of octane rating. If the rating is based on percentage of octane then how can you have over one hundred percent octane.

 

[Ultimatedsm]

Octane rating is just a rating. It is not a percentage. Another side note to you guys, gasoline doesn't have octane in it.

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

Gasoline pumps typically post octane numbers as an average of two different values. Often you may see the octane rating quoted as (R+M)/2. One value is the research octane number (RON), which is determined with a test engine running at a low speed of 600 rpm. The other value is the motor octane number (MON), which is determined with a test engine running at a higher speed of 900 rpm. If, for example, a gasoline has an RON of 98 and a MON of 90, then the posted octane number would be the average of the two values or 94.

High octane gasoline does not outperform regular octane gasoline in preventing engine deposits from forming, in removing them, or in cleaning the engine. Consumers should select the lowest octane grade at which the car's engine runs without knocking. Occasional light knocking or pinging won't harm the engine, and doesn't indicate a need for higher octane. On the other hand, a heavy or persistent knock may result in engine damage.

Bottomline is, if you are going to run high boost, stick with premium, if your not going to boost much or run high boost, than you can go regular.

 

[ilikespeeding]

Octane rating is just a rating. It is not a percentage. Another side note to you guys, gasoline doesn't have octane in it.

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

Gasoline pumps typically post octane numbers as an average of two different values. Often you may see the octane rating quoted as (R+M)/2. One value is the research octane number (RON), which is determined with a test engine running at a low speed of 600 rpm. The other value is the motor octane number (MON), which is determined with a test engine running at a higher speed of 900 rpm. If, for example, a gasoline has an RON of 98 and a MON of 90, then the posted octane number would be the average of the two values or 94.

High octane gasoline does not outperform regular octane gasoline in preventing engine deposits from forming, in removing them, or in cleaning the engine. Consumers should select the lowest octane grade at which the car's engine runs without knocking. Occasional light knocking or pinging won't harm the engine, and doesn't indicate a need for higher octane. On the other hand, a heavy or persistent knock may result in engine damage.

Bottomline is, if you are going to run high boost, stick with premium, if your not going to boost much or run high boost, than you can go regular.

I'm not calling bullshit or anything. But that goes againt everything Ive ever learned about gasoline. I was under the impression that gas did infact contain octane and the octane rating is how much octane vs heptane there was. I was under the impression that most premium fuels do indeed contain added detergents.

Ok: research shows that the octane rating is a perportion of how much ISOoctane vs heptane there is. While isooctane has a 100 rating, heptane has a 0 rating. So, if the octane rating is 91, then for every 100 molecules of gasoline, 9 are going to be heptane. However, that is the perfect way of measuring octane rating. The real world way is to check its resistance against knock and anti-knock ability. So, I was wrong. Im sorry.
Can anyone answer the question about the added detergents? I cant find a source,


source: http://chemistry.about.com/cs/howthingswork/a/aa070401a.htm

 

[Ultimatedsm]

Actual octane is really hard to burn compared to heptane, just look at the chemical properies:


H H H H H H H
HC-C-C-C-C-C-CH <------ Heptane
H H H H H H H

H H H H H H H H
HC-C-C-C-C-C-C-CH <------ Octane
H H H H H H H H


Which chain will break down faster? Just plain old chemistry . The "H"s or Hydrogen is suppose to go over the "C"'s Carbon, but this forum thing isn't letting me. Anyway, you get the picture right.

 

[ilikespeeding]

Actual octane is really hard to burn compared to heptane, just look at the chemical properies:


H H H H H H H
HC-C-C-C-C-C-CH <------ Heptane
H H H H H H H

H H H H H H H H
HC-C-C-C-C-C-C-CH <------ Octane
H H H H H H H H


Which chain will break down faster? Just plain old chemistry . The "H"s or Hydrogen is suppose to go over the "C"'s Carbon, but this forum thing isn't letting me. Anyway, you get the picture right.

Accutally, Gasoline's major contents are isooctane (which is very different from octane) and heptane. Octane and isooctane are isomers, that is they have the same chemical formula but different structures.

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Octane

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Iso-Octane

 

[dyno_detour]

I read an article in USAtoday that said most cars that are suppose to use high octane (91+) can get away using a lower octane fuel. I've had my 95 GS-T since 97 and I always use premium fuel. How much performance will I lose by using a lower octane? I know the 4g63 won't like it, but it's cheaper. Will it take away from the life of the motor?
Thank you!

Ryan

 

[mikejm7]

The reason that we use premium fuel in our dsm's is because they are turbocharged. Any car that came from the factory with a turbo is recommended to use premium. The reason they do this is because under boost higher octane fuel is more predictable in the way that it burns. Using lower octane fuel especially if your car is modded could run you into problems with detonation and knocking is not good. My advice don't risk it. Unless you need a reason to build yourself a nice clean new engine.

 

[-DSM2NR-]

Don't do it. That's My answer. I once let my dad drive my car (big mistake) and he accidently put regular in. The car pulled and felt like shit. In fact, a nearly stock, turbocharged volkswagen beetle beat my car because of this . That should give you a hint of how much power you'll lose

When I realized that my car had regular unleaded in it I drove the car til the gas tank was empty and refilled with good ol' Premium. Then I found that saw beetle and deliever some OWNAGE.

 

[perley03]

"It turns out that heptane handles compression very poorly. Compress it just a little and it ignites spontaneously. Octane handles compression very well -- you can compress it a lot and nothing happens. Eighty-seven-octane gasoline is gasoline that contains 87-percent octane and 13-percent heptane (or some other combination of fuels that has the same performance of the 87/13 combination of octane/heptane). It spontaneously ignites at a given compression level, and can only be used in engines that do not exceed that compression ratio."
http://auto.howstuffworks.com/gasoline3.htm

so who is right because i sure am confused.......

 

[l3igl3ang]

If the US takes over a place that has oil..shouldn't our gas be cheaper?

With bush in office i wouldnt expect to see any gas price drops any time soon. Hell he owns a bunch of oil rigs so hes makeing alot off the gas as well and before bush got in office we never had such high gas prices. I think its BS cause some of us dsm'ers bought are turbo charged cars before the price theiveing so if u want to use 87 octaine i say go for it.


lucky for me i have both tubro and N/T so i use my N/T till these thevies drop the prices.