Hi FitFreakers,

Here in the Southwest, regular gas is 86 Octane. I have burned that in our 2008 Fit MT for the full two years we have had it....and it purrs like a kitten. Not only that, but our two-yr gas mileage is 41 mpg, calculated manually.

I am heading up to Colorado next week, and if I am not mistaken reg gas up there is actually 85 octane. Whatever......the Fit will still run like a top.

 

A few posts have mentioned it, but there is absolutely evidence that the Fit's ECU runs more ignition advance with fuel higher octane than 87. I've logged it myself on my own car, on dozens and dozens of controlled runs (a search using my screenname should bring up the thread & data pretty easily). Now, I haven't seen or read anything to indicate that the computer can "tune up" in the presence of higher octane fuel - the much more likely scenario is that the baseline ignition maps are set up to run with the higher octane fuel, and the computer just retards ignition until pre-detonation doesn't occur. So basically, just like every other car with a knock sensor - the difference here is, I believe the baseline ignition map is targeted for higher octane fuel than is recommended. The manual does clearly state it's designed to be used with 87 or higher, so obviously Honda has faith in their pre-detonation detection system.

Now, whether or not the fact that the engine runs more ignition advance with premium fuel presents enough of an argument to warrant the staggering $3 per fillup expense . . . that's up to you. For what it's worth, I've seen little to no difference in mpg or driveability since switching to 93 octane about 6k miles ago. And if there's more power, it's not enough to feel with a butt-dyno.

 

Make sure not to mix up RON octane ratings found overseas with the AKI rating we use.

 

damn son, I paid 21$ and got 9 gallons using super unleaded lol

 

Back from the dead!!!!

Gas was more expensive 9-10 years ago if I remember correctly.

 

Oh the endless debate.
My 2016 Honda EX manual says 87 OR HIGHER....so 87 would be the minimum, not a specific octane ONLY recommendation.
The manual also recommends usage of Top Tier fuels.

My approach is that I mostly, primarily just run regular, which in my area is 87 octane.
Every 2-3 months? Just for kicks, I'll run a full tank of Premium.
Corresponding with Oil Changes, I usually run a treatment of fuel system cleaner Techron.

Does the Premium make a difference?
I don't really notice it, except the cost for the fill up is more.
Does the fuel system cleaner make a difference?
I don't really notice it.

But in both cases, as just an occasional ritual? It doesn't cost too much.

It's just preventative habit. Something I do "hoping" it might help.
But I'd probably be fine running regular 100% of the time. I can't say I notice a real difference in anything between running the two.

 

honestly, I feel like the mods should squash all these "WHAT OCTANE DO YOU USE" type of threads

it sparks discussion and senseless debate




most of us here know, using higher octane does nothing. it would be really awesome if there was a way to show the others this and/or not discuss these matters in future threads that pop up (and should be immediately closed if I were a mod)

 

oi, i beg to differ! :P

 

The older I get, the more my mind is enjoys repetitive debate. This has to be the umpteenth time I've drug out my boring commentary on what my approach is.
We need some of these repeatedly familiar ground topics.
Deja Vu can be fun!

Next thread?
Top Tier Premium? Worth the investment?

discuss.....

 

lmao, cheers.

i'd like to see some long term results. All the car and driver reporting is based on the short term tests. I want a 100k miles 87 vs 100k mile 93 comparison.

 

if you have some logs of some sorts to share, you have my undivided attn


myself being ktuned.... I CAN tell the diff when switching from 87 to 91 Oct. untuned.... as far as I know/can tell.... there is no diff when switching octane. I know this isn't scientific.... but I do know the ktune can advance timing when using 91 Oct and retard timing when going done to 87 Oct. can we get honda to confirm for us all, when one sticks 91 Oct into a car rated for 87, if said car can advance timing and make use of its higher resistance to detonation?

 

I too am not aware of a stock cars ability to tune itself. if someone has info otherwise, do share and dazzle me

I ran a long term test on mpg, about 1 yr/30k miles worth of fuel receipts and fuely.com data and my findings (non scientific) are = no gain nor impact on mpg... rismo can back me up on that. and... power gain is nice on a ktuned car when on 91 Oct... my bank acct advised against it, and I did eventually go back to 87 Oct