If you do not understand what scan gauge data is or what it implies I could see how you would still be grasping at straws to save face.

Hows this "sparky," you go pay for dyno runs to tell us what the ECU already has.

Also note this is an Eco forum, they arent interested in making more power which is probably why none of them would throw their stock Fit on a dyno @ $75/hour when they can spend an extra $2-3/tank and see for themselves.

 

I saw an old episode of Fifth Gear of Top Gear where they discussed the use of "brand name" premium in different cars and in the STi they tested, the car gained 10 ft/lbs of torque when comparing Shell Optimax, BP and offbrand premium.

If you go and look for it, you'll see the episode and they didn't just test hi-po cars either. The commuter car they tested I can't remember what it was, so I don't know if it had 10:4:1 like our cars do, but I will say that in that car it made 81 hp in all three different gas types, all premium.

You doubters out there, how do you explain how my car runs and more importantly, how much firmer it shifts from gear to gear

 

My scientist brother told me that when they test growth hormone on children they insist it be a double-blind study. Because even something as obvious as how tall a kid is needs to be tested according to scientific principles.

I used to use an oil additive in my diesel rabbit- a car with only 48 hp. And I was convinced that it was faster- that I was at a higher speed leaving a tollbooth that I drove through every day after starting to use the additive. I thought this was rather objective because nobody moved the tollbooths or the spot where the guardrail started.

And then I read of studies that showed that the additive was worthless.

People believe what they want to believe; the mind is very powerful.

I have a friend who's convinced that using synthetic oil has increased his engine power significantly and has also strongly reduced his fuel consumption.
Yet somehow the makers of synthetic oil haven't managed to quantify this and brag about it to sell more of their product?

I have a friend with a Fit (hers is base, mine's sport) and maybe I can convince her that we should do a test when we're both low on fuel- run one on regular, the other on premium, then repeat the comparison again switching fuels, on the same road at the same speed.

Conditions from day to day won't be the same but at least relatively between the two cars we might learn something. Ideally the best way would be to drive the same stretch of road in both directions, then drain the fuel tanks and switch fuel, but that's a bit too much work for me.

 

Um, because I'm not the one making the claim?

And Brian, you are exactly correct. It's called the placebo effect.

I see guys all the time putting CAIs on e36M3s, then swearing the car runs faster. When they see the actual dyno results that they've either: a) shifted the power band slightly, with no net gain, or (more likely) b) actually LOST power (but it sounds cool!), they go back to the stock airbox.

 

I can't help but think of a person that was having a problem with athletes foot.... I told them that I wore wool socks and never had the problem after doing so and asked if they had ever tried that or had worn wool socks before.... The reply I got was that they had never worn wool socks before, followed by "They make my feet itch".

 

Although the wind is going to be different when I got back home to Detroit in the spring I know this, 39 mpg going back and 41.2 mpg is my best to date with the slightly larger tire/wheel combo, but that was with the ECU having learned the 87 octane fuel. Now I have TWO reasons for winter to end

I guess this is what happens when you don't have a perf car and you've got a car that's known for mileage, kinda funny when you think about it, guys arguing about mpg instead of MPH

 

@M3driver and Brain Champagne:

First, let me apologize for the very rude way the truth is being brought to your attention by some of the people here.

Second, I would like to direct you to the rest of this thread. The preceding 17 pages do indeed have a wealth of links, for and against, without which you will have an incomplete understanding of the issue. Your arguments will have a better foundation when you actually see the technical details of how these different fuels affect our L15A engines.

Third, I'd like to present my own experience (again).

To start off: I don't call it premium fuel, because in most respects it isn't "better" per se than 87 fuel, just different. 93 does have certain properties which make it more desirable for use in some engines than other fuels.

Before I learned about spark advance and when I knew little about compression ratios, and when I knew very little about the Honda L15A engine in particular, I decided to take my first Fit Sport (auto transmission) to the drag strip to see how it would do. I had already bolted on an exhaust and intake, and I probably already had my header on as well.

I asked a friend of mine about such things, and he said guys would fill up with race fuel beforehand to get better times. I wasn't about to pay $9.00 per gallon just for a few tenths of a second, but I thought there might be something to the idea, so I filled up with 93 fuel on an almost-empty tank.

Before long (maybe a day or 2), I noticed a difference. The engine actually felt the way I thought it should. I had been putting performance parts on, but while they gave the car more power and slightly better mileage, they didn't help the fact that when I wanted to take off from a red light, the engine took forever to get up to 2000 RPM, where it finally had some power. 93 fuel gave it a faster response up to 2000 RPM.

After a while, I used up that tank of fuel, and filled up as usual with 87 octane.

Within a day, I was almost cursing myself for having done so. The "old" engine was back, pokey as ever. I never went back to 87 after that.

Later, I did some research, and found that a good number of newer cars' computers will adjust spark timing on the fly, based on feedback from the knock sensor. Since the Fit is originally Japanese, and is sold worldwide, it makes sense that the computer should be able to compensate for the wide variety of fuels available worldwide. In some countries, for example, you cannot buy anything lower than 91 (R+M)/2 octane fuel.

I also found out that the L15A's compression ratio is 10.4:1, which only 30 years ago would only be found in engines designed for very high performance. The laws of physics haven't changed much since then. 10.4:1 compression ratio will still heat up a fuel/air mixture quite a bit, so if you don't want knock, you have to monkey with the air/fuel ratio and retard timing a little bit, which reduces power and fuel economy somewhat.

Now, then: I have probably said this 2 or 3 times already, just in this thread. I will say it again. Read the following paragraph carefully to avoid embarrassment.

I personally do not believe that the fuel economy gains with 93 fuel over 87 in either my first Fit (automatic) or my present Fit (manual) have been enough to completely offset the price difference between the fuels in Georgia, however the difference in performance is enough for me to justify my personal extra cost. Furthermore, as I explained a few pages ago, 93 fuel was cheaper than 87 in Lincoln, NE, when I filled up there a few weeks ago. (Really, read the rest of the thread!)

My mantra is still: Try a few tanks, and see for yourself. I don't claim you'll become a millionaire with all the money you'll save. I don't claim your car will last a million miles. But I think you might be surprised at the difference, if you drive like I do.

After all, what's the worst that could happen? You'd be out a few dollars, and you couldn't afford that extra Starbucks drink.

 

I did some research and found a few things. First I want to say the EPA stand is if there no knock theres no need for premium. What they dont tell you is theres a Knock Sensor on all car made from 1996 (OBD2) and thats why you dont hear knock. They also dont tell you that the timing is retarded and that extra fuel is used an a lost of power. The argument wont stop hear and it happening all over the world http://forums.whirlpool.net.au/archive/393709

YouTube - Prius More Enviromentally Damaging Than BMW M3 This is interesting too.
The m3 using premium.
I could not find The fifth gear comparison but do remember seeing it a while back.

 

I was looking and found this for my octane junkie friends, This should explain more why horsepower ratings and dyno's dont work when comparing octanes. Octane Boosters Testing - Tech Review - European Car Magazine

And understanding the ecu http://www.europeancarweb.com/tech/0...ing/index.html

 

That reminds me: another member offered to pay half of the costs for 2 dyno runs on my car -- one on high-octane fuel, one on 87.

Also, while we're on the subject: Torco Accelerator Race Fuel Concentrate | Password JDM

 

I have a feeling that offer has been rescinded

As far as the Torco additive.. the don't actually tell us what they are using in the can on the website, I will have to google that I guess.

But they are suggesting that a half gallon would treat a ten gallon tank of regular gas of an unspecified octane, would raise the total volume average to 102octane ( they don't state if this value of 102 is RON, MON or R+M/2) and at $23 for 32oz bottle wouldn't one be better off to just get a 5gal can of toluene for $35-40 from a paint/hardware store and not pay shipping?

Anyways I am looking forward to hearing your mileage report and feedback from your recent E85/Pump gas blending! And whether or not you are still getting occasional CELs for lean condition under load.

Keep us posted!

 

Dyno would not show that much difference, I already dynoed the Fit with premium and except for running lean 14.2, instead of 11.1 in open loop.

As far as Torco, Ive been trying to get Tex to try it. I believe its MMT with possible lead in a xylene base solvent. Even if the lead is .25 grams in the can it would raise 5 gallons 2 full points. Lead is allowed if its lower that .013 grams. Notice how they call it accelerator. I might be wrong about the base fuel but pure xylene costs 100 plus a gallon.

 

@DSM: I'm not getting anything unusual under load, except more torque at low revs. My CEL (P0171 - Long Term Fuel Trim Lean) is an emissions control check designed, I think, to help diagnose things like injector/fuel pump/O2 sensors, where something is preventing perfect stoich.

@SB: Do you have a dyno graph? My suspicion is that 87 will show lower torque below 2000 RPM and possibly up to 2500 RPM, due to lower ignition advance.

Also, the Fit owner's manual warns against MMT and lead additives specifically. I don't know what's in Torco.

Xylene isn't that expensive for me, I get it at the hardware store as Xylol. Be careful pouring it in

 

It was dyno days and the owner did not have any numbers for the Fit so they all took bets and threw my car on the dyno. They didnt run it at lower rpms and knowing what I know now I would have made them do a better run. Anyways from 4500 to red line you can see the graph go up and down like the 02 turning off and on like in close loop. Max hp was 91.1 and Torque was 88.31 at 14.2 which surprise me and them. They expected the Hp to be low 80s and were surprised it was low 90s. But reading the ecomodder site and those guys say the Fit runs 11.1 in open loop at loads higher than 70 at full throttle. It makes me wonder if thats where the mpg gain is. I also agree that the lower rpm torque would be higher, because you can sure feel it compared to Regular.

Depending on the concentration xylene can be expensive.

 

I have to agree with Glenn... I am pulling a steep hill in 3rd gear with an octane booster at 25% throttle at 2000 RPM and can gain revs on it at 30% throttle. Without octane booster I had to down shift to 2nd or use more throttle to stay at 2000 RPM and couldn't gain speed until cresting the top... I take the hill slow because the road is one lane wide there, the folks that live on it have dogs and they have allowed people on the other side to access their land from their property in violation of written easement rights which I guess don't matter any longer now that the easement is now designated a county road. ... Those people have a tendency to shoot down the hill in trucks and big SUVs denying the right of way to uphill traffic in violation of the law.... At least I don't have to off road it to reach my place anymore.

 

I think this explains the variables http://www.kennebell.net/techinfo/ge...tVariables.pdf

 

Very nice.

10. Fuel octane, and
11. Fuel octane, Ignition timing and Boost

Those 2 points explain a lot right there.

12. IAT sensor explains why my warm air intake improves my MPG: less fuel per charge means more miles per gallon, at the expense of power.

 

When I seen this, I had to post it. At WOT I have 27 degrees timing which puts it right at 93-94 octane.

 

The majority of the info in that .pdf is solid and useful, however a good portion of it is way oversimplified.

How much power you make or lose on individual degrees of advance or retard is not something that is uniform car to car or even engine to engine in identical cars.

The several places he says 4*-16HP or 1 octane point per 1psi do not really hold up in the real world across the whole spectrum of gasoline applications.

You can pick up >16HP on 1* of timing in some setups. You can pick up 30HP on 1 psi boost in some instances. There is also a point at which you see no gains or actually lose power by adding timing. There are also instances where you can make power by retarding the timing, some cases like drag cars with huge cams, turbos and oxygenated fuels have people running ramped timing to the +20's and then at one point flipping as far as -50* of timing.

Also as far as 1% loss for every 10F increase.. again another oversimplification. You can lose far more than that if the ECU decides it needs to pull timing because the charge temp is high enough that the required activation energy is so little that the engine could knock or "diesel" on the compression stroke alone before spark is introduced. And lose yet more if this makes the ECU enrich the mixture a few points.

Obviously Kenne Bell and his engineers are bright guys with decades of experience individually. But some of that was misleading and in some cases just... wrong.

An important one, that you are well aware of SilverBullet, is his statement suggesting the you would need 1.5octane points per psi. There is far more to fuel quality than simply the octane constituent.

So by that metric it should be impossible for me to run 19* of timing and 28psi boost on 93oct...

 

Its an oversimplification and under a controlled temps in might be more true. It just goes to show that theres variables in the variables.

I think S/D was talking about his E50 mix, I dont think he has a turbo. I was just pointing out that if 20 degrees was 87 and 1 octane point equal 1 degree then at WOT I see 27 degrees timing that would mean 93-94 octane fuel.