I'm just gonna post all the logs I ran over the past few days - after people have a chance to watch them we can discuss . . .

Step 1: Download ScanXL ELM from here.

Step 2: Download my configuration file (.cfg) and all the log files (.lgf) here (right-click save-as). Go ahead and extract them to wherever you want.

Step 3: Install ScanXL - you can run it unregistered to view log files. It'll ask you to connect to a vehicle, just cancel out of that. It'll probably also ask you to create a vehicle . . . you can put in whatever you want in, but my vehicle is an '07 Fit Sport MT.

Step 4: Load the configuration file - go to 'File' and 'Open Configuration', then choose the .cfg file I used.

Step 5: Go to the Graphs tab, and open up any one of the log files (ctrl+O). Click on 'Load from File', and pull up whatever one you want to see at the time.

Step 6: You'll see playback controls at the bottom of the window

Step 7: Debate endlessly.

 

too many instructionssssssss. can't you just post your data on here?????

 

General info about my car: 2007 Honda Fit Sport MT. The few upgrades that might affect the numbers are an Aspec CAI and Beatrush underpanel - I've got AMSOIL 0w20 oil in there. Testing was done running Shell 87 & Shell 93 octane fuel - both test days were comparable temperature, ~75F. But IAT's & ECT's are gonna be a better way to compare among runs (some runs were a little hotter than others, but mostly comparable).

The 93 runs were done after filling up with 9.183 gallons of premium, then running the car for ~245 miles. The 87 runs were done after ~510 miles of running regular again. Total mileage on the car is currently 34,395.


edit: Oh - one other thing, I did try and get some steady-state highway cruising logs, but wind was an issue so they were inconclusive.

 

I just did.

People can draw their own conclusions, I'm not big on spoon-feeding.

 

i guess my question is buy bother using 93 octaine on a 87 octane programmed ecu?

like putting a huge rear wing on a front wheel drive car. lol

 

+1
I agree.

Interested but why don't you just post what you found?

 

I thought that there were going to be some results that we would be able to draw conclusions from..... What happened? Was the ECU reset before changing to premium and again to regular? Why only 245 miles on 93 octane, and 510 on 87?

 

Awaiting some discussion...

 

this thread = FAIL

 

Agreed. I'm not fond of installing software I never heard of just to see some numbers, when I can see numbers just by typing 1234567890, or when someone else just needs to do a bit of copy/paste. Please?

 

The owners manual doesn't say that the car is programmed to run on 87 octane, It says not to use fuel with an octane rating below 87.... I think that huge rear wings are goofy on most street driven cars, never could figure out why people do that or put huge power robbing wheel/tire combination on their cars either.

 

Holy crap you guys are lazy . . .

If it were as simple as just posting a few numbers and easy conclusions, I would have done so. But it's not a simple question, and there's not a simple answer to it. Hence, the reason I posted the logs for people to check out for themselves.

That's why I'm testing it. Take a look at the data, see for yourself whether you think it's worth it. I still haven't decided yet, but am leaning towards using premium now.

waaaay off topic, but front wheel drive cars can use downforce just as effectively as rear wheel drive. :shrug:

 

ECU was not reset. Knock sensors & ignition advance set themselves pretty quickly - only takes a few minutes of driving before the ECU adjusts to the new fuel.

I ran on 93 for 2 weeks - the tank lasted 245 miles before I needed to fill up again (my commute sucks). I then switched back to 87 for the weekend (drove up to NH to see family/friends), so it was about a tank and a half on that gas before doing the second set of datalogs.

 

yes, but downforce on the back of a front-wheel-drive car only serves to reduce downforce to the drive wheels.

 

Adding weight to rear wheels desn't affect the weight on the front wheels. The balance is affected but not respective weights.

 

The manual says 87 octane is minimum. Any octane greater than 87 up to probably 105 is acceptable but it doesn't mean that higher octane is of any benefit at all.
And its programmed for gasoline that doesn't pre-ignite at 87 octane rating or above. The only thing that changes it is a signal from the knock sensor that reduces spark advance.
Advance changes with rpm and load so unless you did this in lab conditions its even more suspect.

 

but wouldn't it pop a wheelie with so much down force in the back?

 

oh, i see.

but if you can't tell a difference between a bigmac and
true charburger, why not just eat the cheaper bigmac
and call it a day?

 

Unless you also ran heats of combustion and octane ratings on both samples tested your tests are likely not tom significant statistically.
Those numbers change enough day to day to make your data inconclusive.
And I'm curious why you think its so important to show premium is better than regular in spite of being less economical?

 

mostly? You should see what small differences in the drive program result in very different mpg ratings for EPA?DOT. Unless the testing is done in very controlled conditions as found in a lab its more suspect than real.