Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB

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- - Premium vs regular fuels (https://www.ft86club.com/forums/showthread.php?t=102811)

Quote:

Originally Posted by V_86 (Post 2581397)

There's no 93 really in any of CA, I've never seen it in Socal. It sucks because I would like the mpg gain and fewer lost ponies to 91.

Quote from other forum:

Monterey
Mazda Raceway - Laguna Seca
Hwy 68, Monterey http://www.laguna-seca.com/
Drive in and look for Fuel Sponsor Signs
Fuel supplied by Bryant Fuel, credit card only.
100 octane unleaded at the pump 2/10/11
Fuel pumps are open to the public in the paddock area during normal business hours.
Laguna Seca is a Monterey County Park. Admission/Day Pass is $6.00 when there is not an event in progress.

I use raceway when it's open to public.... well when it was...

Premium vs regular fuels

Quote:

Originally Posted by PureShield (Post 2579718)

My local clubs tuner at Drift Office has tuned and modified over 180 FR-S/BRZ's and has done extensive testing using Canadian 91/94 vs American 92 vs E85 and has shown that are gas is far inferior especially when dealing with a force-fed motor.

How about don't believe everything your tuner say unless you understand it too?

Canada and us fuel rating is the same....

Not to mention fuel varies a bit from stations to station too. If he is just saying fuel @ this station is better then this other station that's ok. But the entire country? What you smoking?

Sent from my iPhone using Tapatalk

Quote:

Originally Posted by mav1178 (Post 2581494)

That's not my point... ECU tune doesn't tell me what octane the gas has, or whether the station had just a bad batch of gas or whether it was systematic in the entire area.

To use ECU tune as a gauge of how good or bad gas is in an area is akin to me gauging the weather of Alaska by seeing what flies over from Siberia...

-alex

No but if both the tunes are the optimal tune for the current setup and the only difference is the fuel that could say something.

Quote:

Originally Posted by PureShield (Post 2582114)

No but if both the tunes are the optimal tune for the current setup and the only difference is the fuel that could say something.

Ya but the same fuel from the same station can change from one day to the next much less comparing from stations in different places. It is possible that they can create more power due to some of the additives that are still used in the US but banned in Canada but even those are at such small levels that I doubt it.
Octane does not produce HP anyway so saying it is higher HP because of octane level is misleading.

Quote:

Originally Posted by chaoskaze (Post 2581610)

D

How about don't believe everything your tuner say unless you understand it too?

Canada and us fuel rating is the same....

Not to mention fuel varies a bit from stations to station too. If he is just saying fuel @ this station is better then this other station that's ok. But the entire country? What you smoking?

Sent from my iPhone using Tapatalk

I have lots of reasons to believe him and I also question what anyone says as well. Canada and US fuel may be the same but his testing (Drift Office, the guys who work with EcuTek personally to solve and improve software problems) has found it to be different. Moral of the story is Chevron 92 american is better for FI/Tuning/Dynoing than Chevron 94 Canadian.

Quote:

Originally Posted by PureShield (Post 2582114)

No but if both the tunes are the optimal tune for the current setup and the only difference is the fuel that could say something.

So what does that say?

That the tune is optimal, or the fuel is?

I really think you are missing what I am saying: ECU tunes are not a reliable method of gauging gasoline (octane) quality.

Just because a tune works well in one area and not for another does not mean one area has inferior gas. Hell, most people equate cheap/inferior gas w/ Costco, and they have some of the most consistent gas you can buy on the market.

-alex

Quote:

Originally Posted by Tcoat (Post 2579416)

How is this even a question? read the manual. It will tell you what you should and must use.
The octane levels are for reducing knock ONLY! Higher octane fuel does not give you more power really. What it does is allows the engines with learning ECUs to adjust the timing higher. This is where the "more power" is created.
As a society that identifies higher numbers as being stronger or better I think many people totally misunderstand octane rating. High octane fuel is intended to reduce preignition in high compression engines it is not stronger or better than low octane fuel in any other way. To grossly over simplify what is happening the higher the octane fuel the harder it is to ignite not the other way around. Sure you can run high octane in a regular engine but it is not doing a single thing for you. You should not run lower octane in a high compression engine though since you run the risk of damage. New engines with self adjusting timing this risk is not huge but run too low in an older engine and you better be good at fixing it.

:thumbup::thumbup:

Quote:

Originally Posted by V_86 (Post 2581397)

There's no 93 really in any of CA, I've never seen it in Socal. It sucks because I would like the mpg gain and fewer lost ponies to 91.

Yes, there is... sort of.

http://www.davebarton.com/Unleaded_Racing_Fuel_in_SoCal

There are 76 stations that sell "racing fuel" (100 octane?). There is one in Pasadena at Glenarm and Arroyo Parkway. But, as someone mentioned above, it's about $9/gal.

OTOH, you don't have to fill your tank with 100 Octane. Just a few gallons per tank should get you to 93 Octane.

@Tcoat does sugar free maple syrup have less octane than the regular kind?

http://www.canadiangifts.com/maple/images/mpg08.jpg

Quote:

Originally Posted by Hotrodheart (Post 2583169)

@Tcoat does sugar free maple syrup have less octane than the regular kind?

It is the E85 of the maple world. It will give you a boost but you need to use way more of it.

Someone in Canada must be using ethanol fuel made from maple syrup.

AFAIK Octane rating are measured in a weird anchient carburetted test engine in a lab under lab controlled conditions, it gives an octane number that you can relate to other fuels tested in same test engine , but fuels may perform differently under differnt conditions in real world engines and engines using dofferent compression ratios and fuel injection methods.

kind of like the fuel economy figures produced for cars what they achieve under controlled conditions is usefull to compare two different car , but real world economy may differ considerably

see here http://www.fuelexpert.co.za/octanetesting.php

Quote:

Originally Posted by emishor86 (Post 2579312)

Hey all,

Wondering if the ZN6 or ZC6 engine performs better with a more expensive fuel like "BP Ultimate" or "Shell V-Power". From research I've done, only sport cars seem to gain a few HP however normal family vehicles gain no benefits.

So is it worth it in a FRS or BRZ?

:thumbsup:

Quote:

Originally Posted by Tcoat (Post 2579416)

How is this even a question? read the manual. It will tell you what you should and must use.
The octane levels are for reducing knock ONLY! Higher octane fuel does not give you more power really. What it does is allows the engines with learning ECUs to adjust the timing higher. This is where the "more power" is created.
As a society that identifies higher numbers as being stronger or better I think many people totally misunderstand octane rating. High octane fuel is intended to reduce preignition in high compression engines it is not stronger or better than low octane fuel in any other way. To grossly over simplify what is happening the higher the octane fuel the harder it is to ignite not the other way around. Sure you can run high octane in a regular engine but it is not doing a single thing for you. You should not run lower octane in a high compression engine though since you run the risk of damage. New engines with self adjusting timing this risk is not huge but run too low in an older engine and you better be good at fixing it.

Quote:

Originally Posted by VTEC (Post 2579472)

It all depends on the OEM tune. The FR-S and BRZ were tuned by factory to use 93 octane under North American rating. I think for you in Australia your system rates that as 98 or 100?

Anytime you use something below factory settings, the computer will detect that because the fuel will start to detonate when it's not supposed to. The computer will detect the explosions and compensate by lowering the compression and horsepower to prevent more premature detonations. So it's not so much that you gain power by using the factory recommended fuel, you lose power by using the cheaper fuel.

If you put something with higher octane and more expensive than the recommended fuel, the computer has no way of knowing that. You will still get the same 200 horsepower on 100 octane that you get with 93 octane. You would just be wasting your money on more expensive fuel with no added performance.

The reason why family cars get no benefit from premium fuel is because they are usually tuned to 87 octane. And if you decide to put 91 octane in your Corolla, there is no way for the Corolla's ECU to detect that. And you would be wasting your money again.

You gotta check the factory specs for each car though. Some sports cars like ours and I think the STI are tuned for 93 octane. Most are probably tuned for 91. An accord coupe V6 6MT is only tuned for 87 octane.

Quote:

Originally Posted by Tcoat (Post 2579520)

Manual says: Recommended 93 Required minimum 91. All is good in the world.

Quote:

Originally Posted by Packofcrows (Post 2579527)

93 you'll notice bit more response and better mpg. Thats it. 91 it feels the same as 93 but with about 3-5mpg less. IMO

I only use Shell 91 or Chevron 91. No 93 in central CA

Tcoat has the best interpretation of this and the manual itself:

http://i.imgur.com/Hcxt1N9.jpg

I use the highest octane ethanol free gas available in my area, which is 91. I've used Shell, which has 93 at some places near me, but I get the crickets. Maybe its in my head? The price difference isn't significant, so I don't mind.