93 Octane?
 

In the marketing materials, it says fuel requirement is 93 octane. Does this mean it will make less hp on 91 octane? :(

91 would be the lowest i'd go. i believe 91 is the lowest 'premium' in the US.

you could fill it with 87 and the car would still drive. you just risk the engine detonating.

http://en.wikipedia.org/wiki/Engine_knocking

Yeah, California only gets 91 octane as the highest available at the pumps. Sucks.

What about 89 octane?

use what the manufacturer recommends, which is 91 or above.

i don't know what the long term effects are if you use anything below, but the engine was tuned with a specific octane rating.

They are all california spec, so 91 is the actual requirement. The marketing materials also say it has a 15" rear rotor.. it doesn't.. unless you live in Japan and use their weird method of measuring rotors..

Curious... what weird method of measuring of rotors?

The smallest wheel size that fits the rotor and caliper assembly = the brake size. So any rotor and caliper that won't fit under a 14" wheel but will fit under a 15" wheel is a 15" rotor..

Weird but interesting, thanks.

Isn't there a difference in octane rating; RON vs. AKI?

Yes but one would assume any US materials would be AKI :)

I was thinking if they forgot to convert it over to the US system of AKI and left it in RON measurements. :D You know, kinda like the rear brake size?

I'd guess the college intern in the marketing department saw the world "premium fuel required" and converted that to "93 octane required" :)

91 AKI is 95 RON anyways I think, so the 93 doesn't make sense for that mistake.

i take it its okay to run racing fuel in these...110 octane?

On a stock engine? Why? lol The engine is tuned to run on 91 fuel. If you were going to rebuild your engine for FI then sure, race fuel would help. But on a stock engine? You are just wasting your $$$.

So we use 91 or 93 then?

Weird, I think all the pumps here are 87, 89, and 91. I could be wrong but... I thought so anyway.

Just add a can of this every fill up and you will be good to go
http://www.energydrinksblog.com/reviews/images/nos.jpg

:bellyroll::lol:

depends on the station, i know my local gas station has everything from 86 to 115, but they are really close to the track

Whatever they sell near you. We don't have 91, just 93 and occasionally 92.

We don't know if the ECU is smart enough to retune itself by advancing timing to take advantage of higher octane fuels. If it's not, you won't only be wasting a lot of money per gallon but you'll be reducing performance at the same time.

I just posted this in another thread, but it is relevant here too:

Normal. Timing will be retarded and fuel economy will drop with performance making it basically pointless to bother.

JUST GET PREMIUM


i think im done here.... if you are worried about paying a bit more for the gas, then you arent ready to pay for the car...

Actually that isn't necessarily true about the fuel economy. We will have to wait and see once we get it in our hands if someone will test several tanks of regular vs. premium.

While different engine, different car the 3.8 GC has no difference between regular and premium. Owners have been saying that for a long time. Doubt we will see much with the BRZ. Probably down on a few HP ~5 but that is about it.

http://sphotos.xx.fbcdn.net/hphotos-...64336573_n.jpg

does the GC have a 12.5 compression ratio?
the GC has a 10.4:1 compression ratio, you can run anything in it
when you are at a 12.5:1 ratio you cant run anything below 91 because the engine will detonate
there is no way anyone should run less than 91, if you do, you're an idiot, go ahead and blow your engine up, shame to see the first 86 off the road cause some dumbass cant fill it up with the right fuel
my celica says PREMIUM REQUIRED so what do i do... fill it up with premium... its easy people... never once did i ask myself "uhhhh maybe 87 will be fine?... yup :D"

Why don't you give Scion a lesson in engine management and proper use of octane rating?

i dont need to, its common sense, if my 2zz-ge has a 11.5:1 compression ratio and someone has tried 87 and had detonation problems, why would a 12.5:1 compression handle 87 any better... or if the car manual says USE PREMIUM, and says it on the gas lid, in the car, why would you use anything different, stop being cheap, treat the car right and give it 91-93 octane

I'm not the one that said I would run regular. I'm just stating that Scion said you could with a decrease in performance. Not sure why you are having an issue with this? It is common sense as you said because the engine can decrease/increase timing as needed.

i was just stating a point and i know you've been here a while and prob know more about the 86 than i do, i was just stating a fact so others could read and i was in no way directing it at you :D

i know the engine can advance and retard timing, but its not worth risking reliability, the only time i would run 87 or 89 is if i had no other choice... as in im out of gas and the gas station im at ran out of premium...

I don't understand why people argue about which octane to use. Use what the car manual states. If you really want to save money then buy a different car. :iono:

or walk

I completely agree 100%. If I get the car I would run premium 100% of the time. But it isn't like the people are asking to run diesel in it. :lol:

As has been disused in many many many many other threads, running premium (whatever it is in your area) will run you about an extra $100-150 a year vs. regular. Cut back on Starbucks and you won't even notice the difference.

Or ride a bicycle.

http://4.bp.blogspot.com/-cfRrkOxrkF...bikenomics.png

:D

Might be worth it for some people to go read about what octane rating really means.

http://en.wikipedia.org/wiki/Octane_rating#Principles

It doesn't mean the fuel has more energy when it has higher octane. It means the fuel is less likely to self ignite. It is when the fuel ignites when it shouldn't that is known as engine knock. Cars have knock sensors these days and will try to reduce engine knock but it really isn't good to put anything less than the min specified octane rating in a car.

You can end up tripping a rev mode that will kill performance and fuel consumption can go up. It just isn't a good thing to do.

I don't understand the argument "If you aren't going to do X, then you can't afford this car."

I'm not trying to brag, but I could pay cash for this car. And, if it doesn't cause damage to the engine, I will occasionally run 87 through it. Maybe I'm just that cheap, but I know if I'm going to spend the day cruising at 70mph, I would prefer to save the $1.75.

Personally I think 1.50 per tank of gas is cheap protection for my engine. *shrug*

The cost of premium is pocket change. The cost of an engine is not. I just don't see why it's worth even the slightest risk. It just doesn't make sense in any way, shape, or form.

I believe it will be possible to run lower octane fuel by restricting the engine torque via reducing intake cam advance...assuming we can get into the software, it should be pretty easy to limit the torque and use lower octane fuel. Another idea I came up with is figuring out at what point of accelerator pedal travel does the engine start knocking at low rpm, and putting a physical gas pedal stop behind the gas lol.

You lose revs and possibly a large amount of torque, but if you're going to be burning a full tank going down the highway on a trip I don't see why not.

I think it is understood that with a high compression ratio and D4S, the Premium fuel is required in North America. That means the AKI 91-93 (with RON 95-97). A current D4 (IS250) owner said that it is possible to run regular (AKI 87) for temporary if necessary, but it will decrease performance and do not rev high on that.

So the 93 octane is AKI 93, not RON 93, I think.