I get those points with my stop & shop card as well. I built up a bunch of them, so I stopped at a local shell. And they wanted 4.50 a gallon for regular. Points or not, bye bye to their ass. That's gas-rape. For me it's 87 and it's between two stations along my route- hess and citko. Whoever is cheaper at the moment. Right now hess is gouging, so screw them. Citko also has full service too. Couple weeks ago I passed an exxon who usually gouges really bad but happen to come back down to earth with a good price so I filled up. It may be in my mind, but I swore I immediately got better mileage on the avg meter and throught the whole tank. I didn't calculate for certain. Eh, whatever- fill me up every two weeks. I'm cool, but I do tend to price shop.

 

I have been disappointed with with the performance I have gotten from Shell since 1994.. I have only gotten worse from Conoco. Citco, Valero, Exxon and Conoco work fine, good mileage and performance.... I actually had the CEL light up when I put Chevron 87 octane in a 97 GMC Safari van.. I thought it was a fluke thing and tried it again with the same results..

 

Honda Fit is designed for 87 octane. Putting in 91 or 93 octane gas is a waste, unless you've installed a turbo, as higher octane gas prevents knocking. As other posters have said, a single refinery may supply multiple brands around the local area. The only difference is what type of additives they put in before delivery (i.e. detergent). Thus, you are not really getting a "better" gas, but you are paying extra for the different additives. If you really want to clean the engine, injector, value, etc, try Techron concentrated fuel system cleaner for two fill ups. It's "certified" by many automotive manufacturers not to damage your catalytic converter or mess with the ECU.

 

Continuing for more than 5 years and thats just on fitfreak. Truth is, as any pedtroleum engineer will tell you, there is no advantage in premium over regular unless you know which feedstocks from which the gas was refined or whether it has ethanol (which lowers energy content).

 

Octane and energy content (BTUs per gallon) are two different things. Ethanol raises octane rating while it lowers energy content (BTUs per gallon). Winter mix of E0 (100% real fuel) is slightly lower than summer mix. I can look up the numbers if someone really needs them.

 

[QUOTE=mahout;1103086]Continuing for more than 5 years and thats just on fitfreak. Truth is, as any pedtroleum engineer will tell you, there is no advantage in premium over regular unless you know which feedstocks from which the gas was refined or whether it has ethanol (which lowers energy content).[/QUOTE


Most petroleum engineers know that from well to wheels the best octane is 94.5 Ron. The only reason that they don't recommend higher octane is the cost of CO2 in air pollution from making and burning which is why they are using ethanol.

Without 93 or higher octane your car would not have been possible. Cars are more efficient because of it. They were able to raise the compression which with out knock is more efficient. The L15 can run regular but you cant prove to me your saving money by using it especially with all the fuel injection cleaner needed.

 

I was getting premium gas for the lawnmower and decided to add some into the new Accord and then topped off with regular. I learned the hard way not to mix BP premium with regular. The car worked better but the gas cap light came on Twice even after my wife took it into the dealer. Its off now but running mid grade. First 2 tanks 21 mpg with regular but the premium mix was 26 and yet to see what the mid grade is but expect the same because the mix was the same octane. I would of never thought that premium would change the pressure in the tank but now I know that Bp premium is different.

 

almost all 87 octane gas uses ethanol, 10-15% ,ethanol burns a lot faster then 100% gas.
you may not notice much difference in the city with 87 octane on your fit concerning mileage, BUT
you will definitely notice a difference in mileage using shell 91 V power gas on the highway.

I used both on a 5000 mile road trip on my 09 fit sport and noticed a significant increase in mileage with shell V power gas on the highway.

so it has been proven and tested by me

 

Wrong, I don't have a turbo or any form of forced induction and required to use Premium in my Fit or else PING PING PING, ECU compensation and loss of power. Gas in Japan doesn't even come in 87 octane so you saying the Fit was designed to use 87 is just laughable as the car was designed and made in Japan originally. Honda in North America states it is alright to use 87 as a minimum because the car is categorized as a super entry level car in the US and because it has a knock sensor and the ECU can compensate for what the engine is being fed through the injectors.

 

finally the truth is revealed!!

 

I'm averaging 39 mpg on my latest tank of gasoline. Good old Sunoco 87 octane.

I have tried higher octane, and noticed absolutely no difference at all.

 

My mileage is lower when I'm playing classical music in the car, and higher when I play rock 'n roll.

 

Something got lost in translation...

Octane in Japan is given in terms of RON, but in the US it's in AKI (RON+MON/2). A rule of thumb for conversion is AKI=RON*.95.
The Japanese Honda Fit manual says to use "Regular" which in Japan is defined as >=89RON. Converting 89 RON to AKI gives an AKI or US octane of 84.5, which I've never seen that low. In the Japanese Fit manual it says, "Although you can use Premium gasoline, it won't change the performance of the engine very much" It's on page 206, you've got a Japanese manual right?

プレミアムガソリンをお使いになることもで
きますが、この場合、本来のエンジン性能が
大きく変わることはありません。

 

この投稿をありがとうございました。

 

I've seen so many of these arguments over the years, but nobody has pulled the Japanese manual translation card ever--on anything. Dayum!

 

It takes a number of things that alone "won't change the performance of the engine very much" to make very much of a change in the performance of an engine... The same thing can be said about the numerous things a person wanting a performance gain has to do to get it.

 

Just want to make it clear that if your new Fit is experiencing knocking with 87 octane unleaded gas (US spec!) , then something definitely is wrong with your engine (maybe due to carbon build up or timing issues or other?) Although 10.4:1 compression ratio on Fit engine seems to be high, it's normal for modern engines and the car should NOT require precautionary measures - like using higher octane gas - to prevent knocking. In fact, if the engine experiences such knocking when using brand name gasoline (87 octane) on a new engine, your dealer will perform diagnostics to identify the cause if still under warranty.

Bottom line: using higher octane on a Fit engine that is not pinging/knocking will not help with performance.

 

For a stock Fit, quality is more important than octane. Honda recommends Top Tier Gasoline

 

And the fact that my ECU has been reflashed requiring premium was lost on some people. The other guy said only need premium if turbo, he was wrong.

Also regular here is 94RON and premium is 99RON. Now do your little calculation once again, something was lost in translation alright, you taking the converted R+M/2 Japanese regular and converting it once again.

 

Japan: Since 1986, "regular" is >=89 RON, and "high octane" is >=96 RON, lead free. Those values are defined in standard JIS K 2202. Sometimes "high octane" is sold under different names, such as "F-1". additional cite.