higher octane rating = higher heat required to burn
higher compression ratio = higher heat from compression

gt86 = has high compression ratio
so you need to use higher octane gas to prevent the gasoline from burning from the compression
- if not, it will cause engine knocking because it will burn before the spark plug ignite it

this will screw up the engine timing

using high octane fuel on a lower compression ratio doesn't do anything, just waste of money

compression ratio is the ratio of the volume of the cylinder when uncompressed vs compressed

Right next to the fuel cap it says "ONLY USE PREMIUM FUEL".

You'd be stupid not to.

Our premium in Australia is 98RON, I think our base is like 91, and I think we have a 95.

I've only ever filled up on 98 in my past 3 cars - that's 16 years... so I could be hazy on the exact poorman fuel ratings.

yep mate I've gone to the 98 side, I'm just wondering if the seller matters because "Coles Shell" sells 98 for $1.30+ around here but I can go down to 7/11 or United for $1.15+ for the same octane...

Guys there a new rule! The crickets sound in the "boxer" engine is actually the diesel component! so fill up with diesel! (sarcasm) (no seriously, don't take that seriously):thumbup:

Always BP Ultimate for me.

I used to use Shell Optimax, but I've found (maybe placebo) that I getter better fuel economy from BP Ultimate, and it's praised by so many car guys.

Caltex 98 for all bar two fill ups and those two were from a Shell servo in Canberra. Wow now that I think about it I've only filled up from one of two specific petrol stations over the entire life of the car.

No hiccups or crickets yet. I would never consider any other grade of fuel unless I was tuned for it like E85 for example.

it's cheaper than shell here in east Melb

Good to know, I heard they put them very low in some cars, and it's very easy to destroy the engine when driving thorughh even modest amount of water.

@CatScan

First off I want to apologize if I came off as angry or insincere I had no intention of doing that. I was off from work today so I did some some data logging and bit the bullet and ran 87 octane for research purposes.


1) My comment of the IAM dropping to zero was in response to your brain exploding all over your keyboard to these dangerous posts:
http://www.ft86club.com/forums/showp...8&postcount=18

The comments you made are quoted and that was what got me riled up so I surmised that you believe it was safe to run a tune for E85 and run 87 octane in it, as well as run 87 in a 91 or 93 octane tune. In fact the way you were typing it out in an unclear fashion made it seem you did it constantly.

Also this comment:
http://www.ft86club.com/forums/showp...5&postcount=28

"Pull the plugs back a bit to lower compression"

I wasn't sure if you were joking or being serious or why you decided it'd be genius to post a picture of an Openflash tablet as an end all comment? You also said "Strange how well the car runs on E85. And for 87" it doesn't run well that's the mistake.

I then commented on a "Bought New car..." thread because you began to suggest it was alright to running incorrect octane fuels with tunes to a new owner looking to start modding:
http://www.ft86club.com/forums/showp...6&postcount=58

I said the IAMs would eventually reach 0 which I have seen on forum posts that I posted on your freak out posts telling me to "show some f***ing proof". You then "hyperbolized" what I said into that it would "DESTROY" a new engine:


http://www.ft86club.com/forums/showp...3&postcount=59

Bottom line you were talking about running a tune and using 87 octane or running e85 and running 87 octane so that's how my logs are done, plus you seem to take things a bit too far on this forum anyway.

Here’s the walkthrough of my logs I'm running an OFH tune and 93 octane all the time with my CNT uel.
Also with UELs I can't run anything else other than a tune otherwise I'll get a P0420 error. Now, of course you can always flash back to the OEM tune in times of dire need but someone else can check what the data logs read for that. I have a feeling with the OEM tune IAM will drop to .70 as was seen in some posts in the software tuning section, it get worse than what I achieved today of the 0 after repeated pulls.

Here is what the logs normally look like on a good day with 93 octane on the new OFH tunes on my AT ZA1JD00D:
http://datazap.me/u/frsbrzgt86fan/co...&data=1-2-8-10

Notice I had almost 0 knock correction except for the slight OFT glitch or something that went -.32 and my IAM stayed at 1 so it should be like that all the time and it looks like the CNT UELs are a good candidate for the OFH specific tunes.
The time in NJ I wasn't actually data logging but looking at the tablet and saw it jump to places like -.72 or -.8 in the kc and the IAM stuck at .87 and jumping around at that.

After being low on gas I filled half my tank up today with 87 octane for a whopping 2.39 a gallon!! This was a giant gas station at a local road called "2nd street Pike", I chose there specifically due to the fact I wanted a long straight road I could do pulls, but I didn't remember that morning rush traffic would get in the way. So I did some pulls up and down that road till I got to 3/4 of the tank and parked in a grocery store and turned the car off and got my Openflash tablet out.

http://datazap.me/u/frsbrzgt86fan/te...ata=1-2-5-9-12

That's what I data logged before the first rest, for some reason the IAMs started at .25 then increased to .9, I also only really got any knock correction at .7 IAM at -.69 degrees puttering through traffic. So I stopped the car and pulled over waited a couple seconds with the car off and OFT unplugged and plugged it back in and started the car and did another pull at around 1/4 of a tank left:

http://datazap.me/u/frsbrzgt86fan/te...a=1-2-5-6-9-12

I was starting to get .5 IAM then it would start rising again all the way up to .93 at the 10 minute mark and I got a bunch of small knock corrections. I then did the same process of stopping the car on the side of the road after going the opposite direction and letting the car sit for a few minutes while I check some text messages. I then did my final 20 minute pull:

http://datazap.me/u/frsbrzgt86fan/te...a=1-2-5-8-9-12

My IAMs reached 0 and I started to get some lean AFRS higher than 14:1 and not on overrun, THIS IS WHAT I MEANT BY IAM REACHING 0, it actually felt the most sluggish on this pull and flkc started to get much more negative.

Take it for what you will, but this is what I meant and you blew things out of proportion and unnecessarily, for me at least here in suburban PA, 87 octane may be of such low quality it causes the IAMs to skitter around and drop and for me to get engine pinging and unusual flkc. Long term this will definitely do some sort of wear, as you described there’s a stretch of your commute where you run 87 octane with the tune repeatedly, if you run the OEM tune feel free to data log as that is much safer than what I did. You're IAM, flkc and knock correction may be more aggressive at the start but remember its correcting AFTER a knock event occurs so there is some sort of pinging occurring for it to try and counter and it may drop to .6 or .7 but that's still pretty bad, and it doesn’t run “fine” or “as good as other octanes” and it’s not “A lawyer making the decision regarding octane, not an engineer." it's legitimately engineers making coherent decisions programming a tune into the ecu that works for a high compression engine with 4 injectors per cylinder. Also if I had pushed it harder like to pass someone I would've totally gotten the engine to knock even more.

unfortunately this is true, it will go on 87, heck put in 85 and it will still go.
Just ask yourself which petrol engine in the world does not run on 87??

You have a total misunderstanding of something. There is no "rule" that they "must be able" to run on 87.
The manual does not say 91 minimum for "liability" reasons.
These are very high compression engines and need the knock resistance provided by higher octane fuel. This is not a matter of opinion or speculation but an engineering fact.
There are many older high compression engines that if you try to run 87 through them they will destroy themselves is no time since they do not have the ability to detect knock and adjust for it.
Being "able" to run on it and should be run on it are not the same thing.


You still have not provided the requested proof that there is a rule that engines must be designed to run on 87.

I gave you an example the 07-10 shelby gt500s they have no knock sensor they may run but the engine will sputter and knock itself to death.

Also that's an efi car look for carbed vehicles like converted lsx and blueprint crate engines and you have a serious problem running under 91 octane

It's as much of a rule as all bicycles must be designed to have 2 wheels ok?

Guys you are taking this octane thing way too seriously. Of course i am not recommending to always use 87. What I am saying is that your car will be fine using 87 with very minimal physical damage to the engine because of modern technology.

At the end of the day, there are tons of Mercedes ML350 owners putting 87 in their 12:1 compression engines without problems.

Consistently red lining your engine will do more harm over time, let's just leave it as that.

That's no proof you won't be able to find any proof it doesn't exist you made it up


Those engines can't be compared to a boxer with completely different characteristics, cylinder material ring material etc.

Knock can kill an engine and do lots of wear especially when it's specifically recommended by a manufacturer and you ignore it. Also what ml350 are you talking about? The gas motor has 10.7:1 compression I believe

I guess thats why 2011 gt500s got knock sensors

They still knock dangerously on the stock tune with anything under 91 if you get into boost. Higher Octane is required in cars with high compression because under high compression the lower octane fuel will combust before TDC, this is "knock"(our FA20). In order for the car to adjust for itthe knock has to occur and it has to adjust and attempt to predict it after the knock occurs for the next knock. That is where the extra wear will occur, in fact it happened to people's di seals in early tunes and FA20s.


However, the GT500s have pretty low compression due to the super charger (I think its less than 9:1). They require high octane because of the supercharger. As long as the sc is not putting boost into the engine, the compression of air should be the factory 9.1:1; this does not require special fuel. But when the boost is applied, even slight throttle, you end up with 16-18psi sitting in the chamber at BDC Bottom dead center
then you compress it by 8.4:1, and you end up with a really high pressure - this requires high octane so it doesn't ignite itself too early. This is a similar issue to the FRS.

The sheer higher compression can cause the pre-ignition, engines with similar compression like skyactiv and such got away with lower octane by cooling exhaust gases quickly and such but the result is less power. The FRS however has some equal length headers and 4 injectors per cylinder etc etc to get us that 200 hp or 100hp per liter...

The bolded I agree with 100%.
The rest of it is bunk.

:thumbsup::thumbsup:

I was with you until you said this.

48k miles, 3+ years, several redlines per week, multiple hard launches at autocrosses that see me bouncing off the revlimiter in the straights and a handful of track days where it lives at >5k rpm for 1.5-3+ hours and the car is stronger than ever. I'll be sure to update when I hit 100k.

:burnrubber:

You were with him that all cars a designed for 87 fuel but they say 91 minimum for liability reasons?
You? Of all people????

Oh that's what he was saying? I was too lazy to read back more than a few posts. I was just going off the '87 isn't a death sentence' sentiment.

Yeah that's fucking dumb.

Oh it is worth taking the time I assure you.

DANG, FRSBRZGT86FAN ...... now THAT was quite a dissertation ..... :thumbsup:

It just lacks an abstract and a summary ...... ;)


humfrz

https://s-media-cache-ak0.pinimg.com...9070e80efe.jpg

Oh, yes ....... NOW I see it ........ :D


humfrz

people are funny.

I just drove 3500 miles to and from Austin, TX. Roughly half the distance was covered by gas stations with only 90 octane premium (and almost $.50-1.00 more expensive than regular 86-87 octane gas).

My car drove fine, did not blow up, and I was able to get 93 octane in time for COTA.

-alex

Sometimes I wish stugray was here.

:lol: It got to the point it got super annoying having a notification every 10 seconds from her saying "post fucking proof"

I think I was the only one up early enough to witness this morning's debacle!

Using anything other than 93 octane
 

If you are living in an area without 93 octane and only have 91 octane......

1:) Use a "Teir One" brand. Favorites are Shell V Power or BP Ultimate. There are 7 times more detergents in them than government of US mandate. It has been proven that "Teir One" gas does improve HP in some cars. Last test I read and viewed video was from England. They used a GTI and the results were quite amazing with the "Teir One" gas. Of course this test was using 98RON gas in England. But the moral of the story was increased HP and gas milege.

2:) If you live in a 91 octane only area......... you can really get to the 93 octane you desire. Lucas Oil Octane Booster is the safest and you only use a half a bottle in each 13 gallon fill-up (pour in before adding gas at pump). Lucas Booster also includes it's fuel treatment in the booster that takes the gummy corn juice and stabilizes it. Most boat owners with an outboard motor will tell you about how corn in the gas kills motors. Lucas booster also lubricates the top end of the motor too. It makes for safer redlines. How much does this cost you ask? $80 for a case of 12. That equals 24 fill-ups that cost $3.33 each. You will easily reap better gas mileage and get back more than the $3.33 you spend using the Lucas Booster.


I'm not a quack. I have tested gasolines and boosters for years on end. I have even gotten up to 30 more HP on modified cars. I recommend Lucas Oil Octane Booster because of price and the extra stabilizers that take the gunk out of the corn in gas. The most powerful booster I have used with real results in NOS Racing Formula. It may not be as safe though. But ask any Harley guy about using NOS Racing Formula in their bike. You live your life with knowledge. I live mine thru testing personally also. All Cali users especially should use the Lucas Oil Booster. They will feel the power within one day of driving. OK. Bring on the hate. Big D

Any proof of this?

The manual recommends using 93, yes, but somehow, I'm doubtful that simply using 93 from 91 will increase horsepower, let alone as dramatically as you describe it.

The fact that you got the name wrong (it's "Top Tier", or "Top Tier Detergent gasoline") somehow makes me question your HP increase claims.

Any of those mentioned in bold to be a big turn off to listening to this guy

1) modern outboards have no detriment to running 10% ethanol, and the myth that it will void their warranties and that tanks they use will get damaged is a falsehood
2)Putting a smiley face on every part of his comment to gain trust of a false belief?
3)"I'm not a quack, I gained 30 hp on my vehicles..." Do you have dynamometer proof?
4) "Lubricate top end with lucas oil octane booster" What? How? How the hell does the octane booster reach the valve-train to help lubrication? Fuel dilution? Not only is that bad for the oil life it could be dangerous.


He preaches the same exact stuff about lucas oil octane booster all over the forum without anecdotal proof of an increase in performance:

http://www.ft86club.com/forums/showp...7&postcount=19
http://www.ft86club.com/forums/showp...4&postcount=26

:popcorn:





humfrz

I Take that old man..
 

I don't post much. I live with myself knowing that research blows away just reading and word of mouth. Corn in motors is bad. Eat some corn just like I did yesterday. Don't put it in your boat motor without Lucas fuel stabilizer. Give Lucas a call...... I spent 50 years at the drag strip. Lucas knows more than you.

Lucas like every other additive company in the market want you to use there products, obviously they will talk them up, I'd like an MSDS of that additive to see what's inside it. Modern outboards are literally tuned for E10 now in fuels. The only issue with them is preventing long term moisture build up.

There are plenty of articles debunking your loss of power belief:

http://www.westmarine.com/WestAdviso...nol-Fuel-Myths

http://yamahaoutboards.com/owner-res...-ethanol-fuels

http://www.boatus.com/magazine/2011/...er/ethanol.asp

http://gas2.org/2011/07/02/5-common-...posed-as-crap/

http://www.permaculture.com/node/490

On older engines yes this is an issue, even on lawn mowers with carbs that don't use ethanol resistant diaphragms and seats but on modern stuff not so much. Also again read the manual it is perfectly safe on stock tune to run 91 on our cars there should be no reason for adding octane booster to that.

Tier 1
 

Gas is rated as tier 1 being the best. There is no top their. Who are you? Just go to the auto parts store and buy a bottle of Lucas. Try it and make sure you do some redline. I can't believe you people haven't tried to raise your octane in Cali. I lived there for 8 years and the fuel needs help. Period.

Yes newer outboards......
 

You're right. Newer motors are made to handle corn. I still think corn is the bad fuel.

Why would I want more....
 

I ask you...... If I noticed better acceleration and better MPG.... Isn't that cool?

Intake and exhaust is a waste to upgrade. The octane boost works. Try it or quiet.

Show me hard anecdotal proof that you gained better MPG and acceleration. Not some subjective number without a dyno test or seat of the pants feel.

Intake and exhaust is a waste to upgrade? The header and tune on my car yield 20-30 hp in the torque dip region, your octane booster can't do that. The FR-S OEM ecu tune is so consistent it will not go past 200 hp at the crank even if you go past 93 octane, the only difference is you'll lose likelihood it will knock if at all.

Do you know how to quote people? because making 3 separate posts in a row to one thread not directed to anyone isn't very helpful.

Gas is rated as tier 1 being the best. There is no top their.
What are you even attempting to say here?

Just go to the auto parts store and buy a bottle of Lucas. Try it and make sure you do some redline. I can't believe you people haven't tried to raise your octane in Cali. I lived there for 8 years and the fuel needs help. Period.

I have a tune and run 93 octane and have datalogs proving that's more than enough, even 91 if I flash to that tune but you lose a minuscule amount of power. On the OEM tune there is no difference.

As for California as to whether or not it "needs help" show me again, some proof, that shows its not good enough for our cars on OEM tune.



The problem really is you're making false accusations and pushing some product saying it'll work, I'm not sure if you're intentionally spamming "Lucas octane booster" but you've made some pretty hefty claims without any evidence. You even went as far as saying it'll increase top end lubrication.