I'm definitely a car junkie, GAFIT. But my main interest, in addition to rolling cars from place to place using controlled combustion of some kind of fuel, steering cars, and stopping them, is in having an understanding of the electromechanical processes used, and in having control of them – being able to take care of any maintenance that is necessary and take care of any repairs that become necessary. I want to rely on myself to transport me from place to place, in my own vehicle, and not rely on someone else; I want to rely on myself to do the maintenance and repairs needed for my vehicle, myself, and not rely on someone else. I don't have enough engineering knowhow to redesign any of the electromechanical processes, but I try to have enough electro-mechanical knowhow, and tools, to do the labor needed to replace parts and to measure and adjust things according how the engineers designed them and service manual specifies they should be adjusted.

For example when I step on the brake pedal, I don't confine my thoughts to how the car is stopping, rather, I also tend to be alert to the fact that I am pushing hydraulic fluid through tubing and that the hydraulic fluid pushes brake pads against rotors, and that the pads are wearing away, and that the brake calipers make a noise as they back away from rotors when I take my foot off of the brake pedal. I'm thinking about how sloppy a job or inadequate a job they did at the factory when they applied brake grease to the back of the pads, or lubricated the pins on which the calipers slide.

I don't live awfully far from the Tail of the Dragon and I am thinking about driving it jn the near future. It's about 2 hours by car from Asheville NC.

 

I am used to using 91 because I typically only drive tuned cars which cannot take anything lower to avoid pre-combustion. My low average has been 39 mpg and high average about 45 mpg using Chevron. I will use Shell if I can't find a Chevron. This is on my fully unmodified GK5 (EX) with CVT.

You should see those numbers drop when my wife drives it though...

 

pump 93/91 shell only for me

 

I use 87 because that's what they say to use.

 

Wish someone would do a dyno run on 87 then run higher octane for a month and do another dyno run. If my FIT was still local I'd do it, but Daughter has it at college..

My 2 bits:
1. Octane rating has nothing to do with fuel quality.
2. Octane is adjusted by the additive package, pretty much all raw fuel starts out at the same octane and gets adjusted up by the package, I was told once that all bulk fuel is made at about 65 octane and the rest is chemistry.
3. Air temps have more effect on power in these cars than octane.
4. in most big cities at best there are 2 or 3 fuel tank farms, they deliver to everybody, there are only like 3 different refining companies left they have all merged. The additive package is added at the farm, not at the refinery..

Cheers.

 

My owners manual says to use 95 octane, for Peruvian cars, and 91 for everything else (I'm in Mexico). I appear to be getting significantly better gas mileage with 92 octane than I got with 87. We only have one brand to choose from, and the 92, besides the higher octane, is less likely to come through with water, or other impurities in it.

 

Some things seem almost hopeless to debate.
Because people have their belief or ritual and they aren't going to change.

I mean, if you believe "gas is gas" and there is no benefit to running a higher octane? Then I'm not going to convince you otherwise.

If you believe running a higher octane results in better performance or gas mileage, then I'm not going to convince you otherwise either.

This is definitely a operator choice situation.

 

Never found a compelling reason to use anything but 87 octane in my Fit.

 

Not making sense. Did you mean Honda Fits manufactured in Peru (are they manufactured there?), or your Honda Fit if it is driven in Peru, and you are purchasing gas in Peru?

There are several octane rating systems in use. For any given batch of gasoline, the MON octane number is about 10 to 12 numbers lower than the RON octane number. In some countries, pumps are labeled with the RON number, in other countries they are labeled with the PON number, which is the average of the RON and the MON. So when specifying octane one shouldn't simply provide a number; one should always include the name of the rating system. In the US pumps are labeled with the PON number. For example regular in PON is about 87. 86 I think is the minimum specified in US owners manuals. In some other countries, that same exact fuel will be labeled 91.

 

Strike That...Reverse It...

OK..totally useless, single person, personal evaluation.
But I ran two tanks of Premium...then 2 tanks of Regular.

At first I thought or imagined the Premium was making the vehicle run smoother.
But now?
Two tanks of regular and I have to say, I don't really notice any appreciable difference.
I DON'T think the vehicle is running any smoother. I don't notice any great loss or gain in MPG.

Therefore, I'm going back to my old routine. 87 octane the vast, vast majority of time.

 

I drove an 1982 accord and I thought it was peppy and adequate. Yet it was not a "drive-by-wire" car. and it was only about 90 hp for about 2100 pounds, so it had a slightly lower power-to-weight ratio than the Fit. For globs sake, I drove a 1968 VW Beetle and I thought it was peppy and adequate. 4 gears. If I had to merge onto an limited access highway the car had sufficient acceleration. There were always some highway access points were the merge lane was too short, but in most cases the car had enough acceleration. Drop it down into 3rd, or even second, and it had enough acceleration. The car could do about 45 mph in second, 60 mph in third, 80 in 4th. Rated top speed, and all-day cruise speed in 4th was 78 but 80 showing on the speedometer was probably actually 78. It could maintain that speed on a mild to moderate incline. 1.5 liter engine. 53 horsepower. New Fit gets almost 2.5 times as many horsepowers out of the same displacement engine and yet the car weighs only 1.3 times as much (and it has the same 850 pounds max cargo capacity). So power to weight ratio was only about 3/4 of that of the Fit. So the 3rd gen Fit is monstrously over-powered (yet it gets slightly better gas mileage).

 

Have not noticed any acceleration problems on my 2015 FIT up to 94 MPH.

If anything, you have to be careful not to get speeding citations.

Don't give this one to a new driver.

 

I find that my 6-speed EX actually runs better on 87 than 91. When I was running 91 for a few months, I noticed a significant torque dip at high RPMs at full throttle. On 87, it doesn't seem to be there. The only benefit I noticed to 91 is a very slightly smoother idle.

 

I prefer Premium/Ultimate, but I have little problem with Midgrade/Silver. Yeah, yeah. I know I'm not likely to drive Yukinko in way that I will see/feel the benefits. But my A500 conditioned me to pay more... just in case.

Price isn't as important, to me, as overall performance and the eco record of the company. BP is better than most... despite their most recent mishaps.

 

Never had a single problem since I drove off the dealer lot.

 

In an attempt to actually record a timing/performance difference between 87 and 91, i set my torque pro app to view ignition timing in real time. As expected, the ecu would significantly advance timing just a few miles into the tank of 91 octane, after emptying a tank of 87. The opposite would happen when id fill back up with 87, after running a tank of 91. On average the ecu would advance 10-15° higher on 91, reaching a maximum recorded advancement of 52° during some spirited driving. The same kind of driving with 87 octane, would record maximum advancement of about 35°, this is evidence that the engine and ecu are indeed capable of utilizing higher than 87 octane. Also its worth noting, after multiple tanks in a row of chevron 91, the ecu has seemed to have settled into an optimized fuel trim for it, because my average mpg has increased by 5 under the same conditions.

 

thanks for sharing this valuable information!

 

no problem! I am used to my old high compression b series motors. I have a strong feeling that the l15b is a very capable little motor, high compression and excellent rod ratio, even better than a b18c. With a few airflow/exhaust flow enhancing mods and a proper tune for 91 or higher octane i can see these motors making 100hp per litre easily. Call me old school but i dont like running low octane on a motor with 11.5 compression, regardless of how much timing the ecu can retard to prevent knock, the idea of it makes me cringe.

 

Really? What kind of MPG were you getting before and after?

I've only done 1 tank of premium just to see if there were any effects. Throttle seemed to be more responsive, but I didn't get any MPG increase. If there would be an increase, I'd have to do the math to see if it's worth the increase in the cost of fuel.

Now that we are in winter, I'm getting 40-42 MPG. Spring through fall, I get 43-45 regular and the stars aligned once where I got 47. This was with 87.