Has anyone tried 100 oct gas in their gt-s?

[Drag-Racing.com]

I'm curious to know if anyone has put their gt-s on the dyno with and without 100+ oct gas and seen any difference in hp?

[erok]

I filled up my GTS once with 103 octane race gas I bought at Buttonwillow race track. The guy working there told me that the race gas has fewer addatives in it than normal pump gas. I think the engine ran smoother and made a tiny bit more power than the 91 octane I usually use.

With all the electronic engine management in the Celica, it makes sense that the ecu would adjust to the different fuel. I'd bet it would show up on a dyno.

[Jnsd]

I always thought that the higher the octane the slower the gas will burn...I don't think it'll make our cars any faster..

My girlfriend just bought a focus, the dealership told her to run 87 octane gas, and that if she ran higher it would only cost more, and she'd get less gas milege.

[DevlynSyde]

A Ford Focus is a bit different than a sports car . . .

[djm221]

Originally posted by DevlynSyde
A Ford Focus is a bit different than a sports car . . .
So is the Celica.

[z6joker9]

Ok... higher octane means it burns slower... thus cars with hotter burning engines run higher octane. A car that uses 87 but puts 93 will not see any good effects, just that the gas wont fully burn, or will take longer to do so.

When a car engine knocks, that is a reason to go up a grade in gas. That's because it is running hot and preigniting the gas. Adding nitrous, boosting, or changing your timing are reasons to go up in gas grade. That's because they run the engine harder and hotter. That's also why you see turboed cars using 100+ octane gas... they can do that and raise the boost alot more... the downside is that they shoot flames from the tail pipe when sitting there, because the car isn't really running hard yet so the gas isn't fully burning, so the gas is spilling onto the exhaust, catching fire, and shooting out of the pipe. This can really cause problems with your sensors.

bottom line, dont use 93 unless you are a GT-S or a GT with nitrious, boost, or timing adjustments...

dont use 87 unless you are a GT

dont go over 93 unless you are boosted and you plan to raise it for the track, or you just want to shoot flames, screw stuff up, and go slow...

[Jnsd]

Originally posted by DevlynSyde
A Ford Focus is a bit different than a sports car . . .

I hate to say it but the celica isn't a sports car....

[Jnsd]

Originally posted by z6joker9
Ok... higher octane means it burns slower... thus cars with hotter burning engines run higher octane. A car that uses 87 but puts 93 will not see any good effects, just that the gas wont fully burn, or will take longer to do so.

When a car engine knocks, that is a reason to go up a grade in gas. That's because it is running hot and preigniting the gas. Adding nitrous, boosting, or changing your timing are reasons to go up in gas grade. That's because they run the engine harder and hotter. That's also why you see turboed cars using 100+ octane gas... they can do that and raise the boost alot more... the downside is that they shoot flames from the tail pipe when sitting there, because the car isn't really running hard yet so the gas isn't fully burning, so the gas is spilling onto the exhaust, catching fire, and shooting out of the pipe. This can really cause problems with your sensors.

bottom line, dont use 93 unless you are a GT-S or a GT with nitrious, boost, or timing adjustments...

dont use 87 unless you are a GT

dont go over 93 unless you are boosted and you plan to raise it for the track, or you just want to shoot flames, screw stuff up, and go slow...


I agree!

[ringthree]

Originally posted by z6joker9
Ok... higher octane means it burns slower... thus cars with hotter burning engines run higher octane. A car that uses 87 but puts 93 will not see any good effects, just that the gas wont fully burn, or will take longer to do so.

When a car engine knocks, that is a reason to go up a grade in gas. That's because it is running hot and preigniting the gas. Adding nitrous, boosting, or changing your timing are reasons to go up in gas grade. That's because they run the engine harder and hotter. That's also why you see turboed cars using 100+ octane gas... they can do that and raise the boost alot more... the downside is that they shoot flames from the tail pipe when sitting there, because the car isn't really running hard yet so the gas isn't fully burning, so the gas is spilling onto the exhaust, catching fire, and shooting out of the pipe. This can really cause problems with your sensors.

bottom line, dont use 93 unless you are a GT-S or a GT with nitrious, boost, or timing adjustments...

dont use 87 unless you are a GT

dont go over 93 unless you are boosted and you plan to raise it for the track, or you just want to shoot flames, screw stuff up, and go slow...

Simple question: Why wouldn't the VVT-i aspect of our cars adjust the cam timing to take advantage of the higher octane?

I run on Sunoco 94 and have notice the engine does run smoother, I thought it was because the engine could advance the timing more?

I am far from an expert on this but I have heard that there is some benefit to running a slightly higher octane even on a NA car. I have heard the explaination you give over and over but even with small bolt-on's the a/f changes enough to at warrent a look into higher octane gas.

[Jnsd]

Originally posted by ringthree

Sunoco 94

Woah that stuff exists? I'm lucky if I can find 91 octane here in san diego! I'm sure higher quality gas helps our cars, but I'm kinda doubtful that race gives us any HP gains...

[BillWS6Formula]

Higher octane gasoline than your car requires will not add horsepower! Octane rating is simply a measure of a gasoline's ability to resist detonation - no more no less. So if you're car is not detonating on the gas you use now, adding higher octane gas will not make you go faster. If your car (which I'm pretty sure the GT-S has...as well as my LS-1) has a knock sensor, then yes it will advance timing until it detects knock, but only to a certain point! Pump 93 or 94 octane will more than cover that ability in a stock NA car. Now if you're running NOS or boost of some kind, then yes gasoline with octane ratings higher than that can be of significant benefit IF the car is tuned to take advantage of it. On a stockish NA car? You'll be faster only in direct proportion to the weight loss realized by running with a lighter wallet ;).

[djm221]

Car and Driver did an article with dyno and track test on a couple of different cars with different grades. Despite them saying it doesn't make it difference on cars that are suppose to run 87, they did benefit from the higher octance fuel. Especially the Mustang GT, gained a couple of HP. They also tested cars like the M3 and an Acura, and they obviously suffered from the lower octane ****.
I think their results contradicted what is always said that higher running 93 octane on a car that requires only 87 will do absolutely nothing except cost more.

[Mr.MOJO]

It may not be a sports car but it has the same compression as an S2000,Porsche ECT.
Therfore, High compression Higher Octane.

[BillWS6Formula]

On cars with with knock sensors, or boosted cars, yes. I owned a 97 Mustang GT and played that game - took it to the track myself and my own results showed NO repeatable difference. Cars without knock sensors or those having no detotation issues simply will not benefit from high octane gas! Such gas has NO additional power boosting ability. Any differences in back to back runs using different octane for such cars will simply be testing anomalies.

But it's your money - if someone thinks the feel good power of running high octane gas in a car that does not need it makes a difference, then have at it. IMO it's power adding ability is just a notch above that added by stickers ;).

[JaySong]

Originally posted by Jnsd


I hate to say it but the celica isn't a sports car....

But if you use that type of narrow definition of sports car, not many cars are true sports cars. many will be considere roadsters, compacts, etc.
It seems like you are defining sports car by how much horsepower it has.
Did u know that a weak mr2 is considered a ports car, so is a miata?

[z6joker9]

Originally posted by ringthree


Simple question: Why wouldn't the VVT-i aspect of our cars adjust the cam timing to take advantage of the higher octane?

I run on Sunoco 94 and have notice the engine does run smoother, I thought it was because the engine could advance the timing more?

I am far from an expert on this but I have heard that there is some benefit to running a slightly higher octane even on a NA car. I have heard the explaination you give over and over but even with small bolt-on's the a/f changes enough to at warrent a look into higher octane gas.

honestly i can't say that i know... i do know that basically in the first line of my powerchip(which is basically a piggyback ecu) instructions, it says i MUST use 93 octane gas because of the timing adjustments that are made when you tune it... if the VVT-i part adjusted the timing enough to take advantage of 93 octane, then why would a company bother to add that feature? I assume Weapon R has been working on our ecu and a piggyback for it, so they may have some insight... someone go ask them

[Drag-Racing.com]

From what I understand there is a difference of about 40hp from the gt-s in japan... The motors are supposed to be identical so the only difference is the ecu and that they run higher octane then we do (they have 100+ at the pumps)

I was told the higher the compression the higher the octane you have to run, we run 11.5 to 1 which is/was the highest available in a regular driven car.

I got free dyno time coming to me, so i'll run my car close to empty and get a jug of race gas and see what difference I get.

Unless our ecu doesn't take advantage of it, I dont' see why we couldn't pickup a bit of power.

[BillWS6Formula]

"Unless our ecu doesn't take advantage of it".

That's it in a nut-shell. Timing advance isn't a bottomless well - depending on the overall engine package there is an optimum point and there's nothing to be gained going beyond it. Again, and I can't emphasize this enough, a gasoline's octane rating is simply a rating of it's ability to resist knock/detonation - that's all! Modern engines with knock sensor's can take advantage of this higher rating to advance timing up to the pre-set limit as determined by the ECU. That's why cars such as the GT-S reccommend premium for best performance. Their ECU's will notice the difference between 87 and 92-94. But that 92-94 is the upper limit for taking advantage of timing adjustment for a stockish NA engine that is in all other respects running ok.

[z6joker9]

japan/europe, if i am not mistake, have a different measurement of octane... 100+ can be equal to 93 here... someone give a more detailed answer on that...

[Drag-Racing.com]

Originally posted by BillWS6Formula
"Unless our ecu doesn't take advantage of it".

That's it in a nut-shell. Timing advance isn't a bottomless well - depending on the overall engine package there is an optimum point and there's nothing to be gained going beyond it. Again, and I can't emphasize this enough, a gasoline's octane rating is simply a rating of it's ability to resist knock/detonation - that's all! Modern engines with knock sensor's can take advantage of this higher rating to advance timing up to the pre-set limit as determined by the ECU. That's why cars such as the GT-S reccommend premium for best performance. Their ECU's will notice the difference between 87 and 92-94. But that 92-94 is the upper limit for taking advantage of timing adjustment for a stockish NA engine that is in all other respects running ok.

Please tell me how you know the Celica GT-S stock ecu from America is only set for 92-94 octane?

If you are just guessing why are you posting like you know or have tested?

Do you even own a GT or GT-S?

[oldster]

Originally posted by Drag-Racing.com


Please tell me how you know the Celica GT-S stock ecu from America is only set for 92-94 octane?

If you are just guessing why are you posting like you know or have tested?

Do you even own a GT or GT-S?

Why don't you perform your dyno and get back with us on the results as it doesn't appear to have been done before.

[lnux-rhat]

Originally posted by z6joker9
japan/europe, if i am not mistake, have a different measurement of octane... 100+ can be equal to 93 here... someone give a more detailed answer on that...

true....i'd say Euro 95 is equal to 91 here
At some pumps you can get 98, which is ~93 in US

[BillWS6Formula]

Originally posted by Drag-Racing.com


Please tell me how you know the Celica GT-S stock ecu from America is only set for 92-94 octane?

If you are just guessing why are you posting like you know or have tested?

Do you even own a GT or GT-S?

To start with, read your owners manual noob....whatever dude...fill yer boots, it's your money, waste it whatever way pleases you most...

[2K1BLKCELGTS]

The local news here had a program that basically said that running higher octane at this altitude (6200 ft) was was useless and that it didn't help anything. I still not sure that I understand that. I suppose that if it is more difficult to burn and we have less oxygen anyway, then it makes sense to use a lower octane.
I thought that I had noticed a little better power using the higher octane (very hard to tell).
In fact the only thing they sell here unless I go to the airport is 85, 87 or 91 octane.
How does altitude affect the burn rate?


Which part of my Celica is not a sports car? Looks sporty, Feels sporty,...must be a ....?

[Oo DaRk StAr oO]

yeah, compression ratios also, if you have a car with 11:1 vs 10:1 then u need more octane. So those NA guys need higher octane as well as a GTS driver. Now if ur boosting with 8:1 thats a diff story. Any type of forced induction would benifit from more octane.

[brothermaynard]

Celica not a sports car = opinion : opinions are like ash holes everyone has one.
I get revved all the time by --real-- sportscars. The car goes 140+ (been there) and brakes like a mofo. Need I say more?


2zzfe has a very high comp. ratio, not 8, not 9, not even 10, no still not there at 11, we have 11.5, and the higher it is the better the chance of detonation ect.

The evidence is out there, and it is indisputible that higher octane will give 2zzfe more power. Other engines can not say the same, the appropriate sensors must exist.

The acclamation time is unknown perhaps imediately or perhaps not. I have put my money where my mouth is, there is a 76 in Bellflower that sells 100 unleaded. I purchased 4 gal. on an empty tank, and tried it over a few days, making sure to do full range reving and full temp. ranges. My butt dyno says +HP. That is just my ash hole's opinion. I did some stopwatch 0-60 times and they were low 6's and that is better than 91 octane at 6.6 sec. (two run avg). Next time I will do more definitive testing but this time was just for fun.

Note: any dyno time must have acclimation time for the computer to adjust.


A dragster is not the only type of racecar. Celica GTS w/LSD and a couple of other light mods and all is well. Off the line is fine but that fraction of time is just a drop in the bucket on a nice road course, where the revs stay high the rest of the time.

Many cars have far more displacement but much less efficient. In addition to that the are loaded with fat. My car is light and has a highly effecient engine. Long live technology my pentium is getting smaller and so is my engine. 100 cubic inches is fine with me, you just have to know how to use it.



GTS is a sports car!

[pensfan83]

GT-S does not = sports car
GT-S = sports coupe

But :whogives:

3000GT = GT car

911 Turbo = sports car

Matrix = umm, uhh, undefinable ;)

[BillWS6Formula]

Originally posted by 2K1BLKCELGTS
The local news here had a program that basically said that running higher octane at this altitude (6200 ft) was was useless and that it didn't help anything. I still not sure that I understand that. I suppose that if it is more difficult to burn and we have less oxygen anyway, then it makes sense to use a lower octane.
I thought that I had noticed a little better power using the higher octane (very hard to tell).
In fact the only thing they sell here unless I go to the airport is 85, 87 or 91 octane.
How does altitude affect the burn rate?

As altitude increases air density, of course, decreases. This leads to lower absolute cylinder pressure during combustion, and thus a lower tendency for detonation (which is directly related to cylinder pressure - the greater the pressure the greater the danger for detonation). Therefore the octane requirement is also reduced.

brothermaynard, you are certainly correct in your statement "the higher it {compression} is the better the chance of detonation". But compression is only one factor which determines the octane requirement. Another is timing advance, while intake charge temperature is yet another. All these factors are taken into account by manufacturers when designing an engine, and in determing an engines gasoline octane requirement. Do you honestly think Toyota designed the american spec GT-S engine to run optimally on 100 octane gas and then export to the land of 92 octane? They'd be shooting themselves in the foot by doing so. There's a reason, divine technological gifting notwithstanding, why they reccommend gas with an octane rating of 92 - that's what they designed it to run with. Same as they designed the GT engine with a reccommended 87 gasoline octane rating in mind.

"The evidence is out there, and it is indisputible that higher octane will give 2zzfe more power." What evidence? Seat of the pants? That's hardly a calibrated scientific instrument! ;) As for "indisputible"...hardly :).

Now if anyone, no matter what their engine or it's technological shortcomings, is experiencing detonation or pinging running their current gasoline, then yes they will benefit from running a higher octane fuel. Some common causes of intermittent pinging troubles are bad fuel, carbon build-up inside the combustion chamber (leading to increased compression), abnormally high air temps (running at the track on a real hot day), and engine overheating, to name a few. Using a high octane gas in these conditions may help. BUT if your car is running ok, with no pinging, and you are using the fuel reccomended by the manufacturer, then using a higher octane fuel is not necessary. Again a fuel's octane rating is simply a measurement of it's resistance to detonation - no more, no less.

As an aside, if anyone does feel the need (for whatever the reason ;) ) of using any of those commercial "octane booster" products, don't expect any miracles. For expamle reading the side panel on the bottle you'll see common statements like "raises octane rating by 5 points...by 7 points..." etc. Well the key part of those claims is the word "points", as in decimal points. Adding a bottle of a product claiming to raise octance by "5 point" to a tank of 92 octance will NOT give you a tankful of 97 octane. What it will give you is a tankful of 92.5 octane gas. The devil is in the details! :)

OK on the "sports car" thing. A book could be written here on that discussion alone LOL! But from my own read on things (and what is losely reflected in the car market from magazines to manufacturers), here's my breakdown:

sports car - fun to drive, superior handling, rwd cars with an emphasis on performance over creature comforts. To a real purist, a sports car must also be a convertible and with seating for two only!. Some examples: Mazda Miata, Chevrolet Corvette, Porsche Boxter, Toyota MR-S, Dodge Viper, Acura NS-X, to name a few.

sports compact car - the new (relatively) breed of fwd performance cars like the Celica GT-S, Acura RS-X, Civic Si, Mitsu Eclipse, etc. etc...

muscle car - old school intermdiate body cars with powerplants from the larger full size cars. IE Olds 442, Dodge Charger, Pontiac GTO, and the somewhat more recent Buick Regal GN, and Chev Impala SS.

pony cars - smaller again than muscle cars with a higher priority (than muscle cars) on handling over just straight line speed. Ford Mustang, Chev Camaro, Pontiac Firebird.

GT - rwd (or even awd) high performance automobiles that all cater as much to creature comforts as all out performance at any cost. Various Jaguars, the late Porsche 928, Supra, 300ZX, 3000GT etc.

sports sedan - 4 (or even 2) door performance cars such as the BMW 3 series, Lexus IS300, Audi A/S4, even the WRX...as examples.

exotics - Ferrari's, Lambo, some Porsches, etc. whose prices transcend any other definition.

All the above fall under the general heading "performance car", and there are many that blur the lines described above. But that's basically how I see it...you of course, are entitled to your own opinions :).

[brothermaynard]

Labels soo many labels...I guess it depends a little on who you ask. I look at it in more of a performance aspect. It turns out a few of those "sports cars" would have a tough time teaching me a lesson.

The matrix is a station wagon.

Excellent points about the octane boosters. Tried em for a short time and I will not do that again. All that before I did the research on octane, which BTW is not understood by most.

A few years back I would ask knowlegable people what octane was and what did it do. I found out it was not an easy question for most people to answer. Over a very long period I really only got one acceptable answer, and that was from one of the product engineers for NOS when I was at SEMA one year. Later I did my own research and am glad I did.

In the end I say yes... you say no... but we can't be sure without some good testing. It turns out that even the best butt dyno has a very high placebo effect error factor.

[nxracer]

Originally posted by BillWS6Formula

"The evidence is out there, and it is indisputible that higher octane will give 2zzfe more power." What evidence? Seat of the pants? That's hardly a calibrated scientific instrument! ;) As for "indisputible"...hardly :).


This one is "calibrated"

[brothermaynard]

You can do better than that.

[2K1BLKCELGTS]

Thanks for the info. I think that I'll try a low octane up Hardscrabble pass. I can gain 5000 ft in 10 miles, (hell of a fun road too!)

That may be calibrated, its obviously performance, but is it blueprinted? I'll volunteer!

[Jesse IL]

With 11.5:1 compression, the Celica could probably benefit from higher octane fuel, but ONLY by adjusting the ignition timing. Japan Celicas are tuned to run on 98 octane fuel, and probably run more advanced ignition timing. I have a feeling that the GT-S does not run at the "optimal" ignition timing given that its tuned to run on 91 octane fuel.

In response to an earlier question, 91 octane is all that's available anymore in California. This has to do with a larger number of vehicles requiring premium fuel there. Here in the midwest, where trucks are more prevalent, we get 93.

[TRD Liquid Silver]

Originally posted by Jnsd


Woah that stuff exists? I'm lucky if I can find 91 octane here in san diego! I'm sure higher quality gas helps our cars, but I'm kinda doubtful that race gives us any HP gains...

the east coast has higher octane gas in their super than we do. when i went back home for a visit in nyc they had 87, 89, 93 and 94.. WOW!!! i do remember when i got my car that san diego, ca had 92 and they dropped it to 91 last year.

[VVT4ME]

Why do different states offer different choices of octanes???????? I thought high octane gas would promote dirtier-burning engines to burn cleaner, so why not? California only has 91????? Doesnt make any sense...

[NoCones]

I put diesel in my GT...I'm getting 250 whp and running 0-60 in 5 flat. Confirmed with my butt dyno and stopwatch. You should all try it.

[jer925]

i'm not totally sure on this but i think that the higher octane race fuels also have more of an oxygen content in them. which could screw the o2 sensor and the computer would proly go nuts.

[2002GT_Celica]

Umm...is the chance of having a performance gain worth the 6 or 7 dollars you are going to spend on one gallon of 100 octane gas alone.

[Calsoldier]

While I was at Sears Point Raceway in Sonoma, CA, I talked to a representitive of 76 (the gas company), and he said to try out the 110 octane for my car, and said it would shave off a tenth of a second on my 1/4. It was 5 bucks a gallon, and I filled up half a gallon, since I had barely any fuel at all. So after I filled up, I ran 0.09 seconds faster than normal, and I think I could actually feel a little more power. Hope that helps...

[Vroom_Vroom]

Originally posted by Jnsd


Woah that stuff exists? I'm lucky if I can find 91 octane here in san diego! I'm sure higher quality gas helps our cars, but I'm kinda doubtful that race gives us any HP gains...

91 in san diego!?? theres 92 all over the place!!

[Jusone36]

ok, looking at the ndra requirements for the nopi fnf series, i saw that you are required to use their gas, a ndra approved type. is this a higher octane gas? anyone know from experience? what's the difference? how would it affect a gt auto with general engine mods?

[DaksGT]

I have a 1zz and used 91+ octane from day one. Sunoco 94 most of the tme.

[MajorA]

There is a place near my house that sells 97+ gas for exotics and stuff and me and my friend split a couple gallons of it. I felt absolutly no difference in my car. I think that people are correct in assuming that the ECU can not correct timing any more than what is possible with about 93 octane. My friend had a 99 gs-t that had been abusued pretty bad before he got it. The race gas gave him a little more percieved power but i think all it really improved was the smoothness....

[analogvoid]

theres a sunoco on the way to the track... i think im gunna try a gallon or two of thier 94 and see if it helps any..

lets see if i can revie this thread...

[iwantaferrari]

i could see it helping. the ECU advances timing until it hears pings through the knock sensor right? when you toss in the slower burning gas id assume it would advance the timing more than normal.....

my car is setup to use 87 octane, but i advanced the timing by hand and use 93 and i make more power... the same priciple would apply if i tossed in race gas and advanced the timing a few more degrees... little bit more power

[RedNOSceli]

I think someone said it before, that a hight actain can only help to a point. Engines with knock sensors will see knock using a lower grade fuel with high compression there for pulling timing and loosing power. Now replace that gas with good gas that wont ping, the knock sensor doesnt see anything, therefore gives back that timing that it was earlier taking away, IE giving more power, but only up to a certain point. If there's no knock at 93 octain, 100 octain wont make difference. I know for a fact that after running 91 piss, and running 108, its a huge jump, better idle, everything...I assume 108 is past the point, I prolly could get the same results with 100, but hey, I had the cash.

[RedNOSceli]

oh, btw, as soon as we see direct injection, it wont matter anyway...87 octain all day long with 15:1...

its all about squirting the gas *AFTER* the compression!!!

[exotic performance]

so if the celica isnt a sports car what is it?

[Griffin]

FYI - an older engine with lots of carbon deposits (or an newer one for that matter) will also benefit from higher octane. The glowing hot carbon combined with the slightly increased compression can cause preignition. also some driving conditions (mild grade at light throttle) can result in pinging in an otherwise healthy engine, and higher octane will help there as well. Mind you in both of these cases the octane is adressing a problem that causes a horsepower loss NOT creating any kind of a gain.

[Apexi]

100 octane couldnt hurt...as long as its unleaded

[NickyTs]

Own3d

[Njay]

In the UK we have Shell Optimax that is a higher uk 98 octane rating than our normal unleaded 95 gas.

It costs 10% more BUT the car is more responsive and returns a higher MPG by 2 or 3 miles which makes up for the higher cost.

However (and this is why I'm posting) it does take time for the ECU to alter and given other's on the Celica-uk website which I also subscribe too, this seems to be by the 2nd full tank i.e. those of you buying your gallon of 100octane and expecting immediate results aren't gonna get them.

What others have found when they have to fill up with normal unleaded (uk 95 rating) is that after using the Shell Optimax stuff, the Gen7 celica is sluggish and won't accelerate as well.

Just my (amongst 1000's of others) opinion ;)

[ArchangelX]

The Celica is a SPORT COMPACT CAR...

Although it looks like a sports car. :D

[Maestro]

Originally posted by Jnsd


I hate to say it but the celica isn't a sports car....

mate....you've lost your ****ing marbels !

the celica is a sports car !!!

go drive your grandma's 82 wagon...while i scream past your stoopid dumb azz !!!